Can't spin the drive shaft when the rear of the car is on the ground and the car is stationary
So Did A Tune Up Last Night, Found Some Disturbing Things -
- Thread starter JenkinsBS
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IMO, invest only what it takes to keep this engine on the road.
Sounds like it's at the end of it's career, which usually means it's going to nickel and dime you to death and probably still break anyway.
Since money is an issue, drive it as is, save up and get yourself an explorer engine.
I drove one of my engines for like 2 years that burned quite a bit of oil and had pressure under 10psi at hot idle.
I've never run across anyone with a 5 liter engine that actually burned oil because of the valve seals, IMO, that thought is just wishful thinking.
Rings and bearings are most likely to go and now and then mix in a bad intake gasket.
Sounds like it's at the end of it's career, which usually means it's going to nickel and dime you to death and probably still break anyway.
Since money is an issue, drive it as is, save up and get yourself an explorer engine.
I drove one of my engines for like 2 years that burned quite a bit of oil and had pressure under 10psi at hot idle.
I've never run across anyone with a 5 liter engine that actually burned oil because of the valve seals, IMO, that thought is just wishful thinking.
Rings and bearings are most likely to go and now and then mix in a bad intake gasket.
LOL good eye, reverse that!! chalk the front and put the back in the air.Can't spin the drive shaft when the rear of the car is on the ground and the car is stationary
2000xp8 - My oil pressure never goes below the half way mark on the gauge, and thats usually when im idling, when driving its at the high mark on the gauge -quick back story is its a MAF converted car, the shop the re did the motor hooked it back up as MAP left the MAF wire hanging there, put the distro 180 out, AND hooked it up in the NON HO firing order, put in an a non A9L ECU in it (thanks a million times over to Seijirou who hooked me up with one) , then drove it around for a bit to make sure it ran, and im sure they gassed it pretty hard just cause its a V8 and they wanted to hot rod it to test it - IDK what horrible things this could have done to the car, but ive corrected all that and have been driving for almost the past year, with the only issues being the smoke out the exaust like in the youtube video, oil leak, and the WOT issue
a91what - When the plugs were pulled, the tips all looked in good shape, marshmallowy color, no burnt black, or extreme white, just a toasty color. Im going to get a compression tester on my weekend (wed /thurs) and do that to the 2, 4, and 8 cylenders first, then the rest after.
So from the video posted to youtube, does that look like buring oil, or fuel to you guys?
a91what - When the plugs were pulled, the tips all looked in good shape, marshmallowy color, no burnt black, or extreme white, just a toasty color. Im going to get a compression tester on my weekend (wed /thurs) and do that to the 2, 4, and 8 cylenders first, then the rest after.
So from the video posted to youtube, does that look like buring oil, or fuel to you guys?
Quit gessing and do some diagnostic work...
compression tester - $26 from AutoZone. Part Number: CP7827
You wont find a mechanic will to do it for the price of the tester.
Paper clip to put the engine in diagnostic mode. 2 cents.
Circuit tester to make up for the fact that your 88 does not have a working check engine light.
Autozone $10 Part Number: 25886
Cylinder balance test:
Revised 25 March 2012 to add necessity allowing the KOEO tests to finish before starting the engine and the need for a properly functioning IAB/IAC to run the cylinder balance test.
The computer has a cylinder balance test that helps locate cylinder with low power output. You’ll need to dump the codes out of the computer and make sure that you have the A/C off, clutch depressed to the floor and the transmission in neutral. Fail to do this and you can’t do the engine running dump codes test that allows you to do the cylinder balance test.
Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
Be sure to turn off the A/C clutch depressed to the floor, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.
Here's how to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.
What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and drivability problems
Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, clutch depressed to the floor and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
Cylinder balance test
If you have idle or IAC/IAB problems and the engine will not idle on its own without mechanically adjusting the base idle speed above 625-750 RPM, this test will fail with random cylinders pointed out every time it runs. The IAC/IAB must be capable of controlling the engine speed to run in the 1400-1600 RPM range. Playing with the base idle speed by adjusting it upwards will not work, the computer has to be able to control the engine speed using the IAC/IAB.
Warm the car's engine up to normal operating temperature. Use a jumper wire or paper clip to put the computer into test mode. Let it finish the Key On Engine Off (KOEO) code dump. Start the engine and let it go through the normal diagnostic tests, then quickly press the throttle to the floor. Remember to keep the clutch pedal (5 speed) depressed to the floor during the test. The engine RPM should exceed 2500 RPM's for a brief second. The engine RPM's will increase to about 1450-1600 RPM and hold steady. The engine will shut off power to each injector, one at a time. When it has sequenced through all 8 injectors, it will flash 9 for everything OK, or the number of the failing cylinder such as 2 for cylinder #2. Quickly pressing the throttle again up to 2500 RPM’s will cause the test to re-run with smaller qualifying figures.
Do it a third time, and if the same cylinder shows up, the cylinder is weak and isn’t putting out power like it should. See the Chilton’s Shop manual for the complete test procedure
Do a compression test on all the cylinders.
Take special note of any cylinder that shows up as weak in the cylinder balance test. Low compression on one of these cylinders rules out the injectors as being the most likely cause of the problem. Look at cylinders that fail the cylinder balance test but have good compression. These cylinders either have a bad injector, bad spark plug or spark plug wire. Move the wire and then the spark plug to another cylinder and run the cylinder balance test again. If it follows the moved wire or spark plug, you have found the problem. If the same cylinder fails the test again, the injector is bad. If different cylinders fail the cylinder balance test, you have ignition problems or wiring problems in the 10 pin black & white electrical connectors located by the EGR.
How to do a compression test:
Only use a compression tester with a screw in adapter for the spark plug hole. The other type leaks too much to get an accurate reading. Your local auto parts store may have a compression tester to rent. If you do mechanic work on your own car on a regular basis, it would be a good tool to add to your collection.
With the engine warmed up, remove all spark plugs and prop the throttle wide open, crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 psi. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.
See the link to my site for details on how to build your own blow down type compression tester.
compression tester - $26 from AutoZone. Part Number: CP7827
You wont find a mechanic will to do it for the price of the tester.
Paper clip to put the engine in diagnostic mode. 2 cents.
Circuit tester to make up for the fact that your 88 does not have a working check engine light.
Autozone $10 Part Number: 25886
Cylinder balance test:
Revised 25 March 2012 to add necessity allowing the KOEO tests to finish before starting the engine and the need for a properly functioning IAB/IAC to run the cylinder balance test.
The computer has a cylinder balance test that helps locate cylinder with low power output. You’ll need to dump the codes out of the computer and make sure that you have the A/C off, clutch depressed to the floor and the transmission in neutral. Fail to do this and you can’t do the engine running dump codes test that allows you to do the cylinder balance test.
Here's the way to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
Be sure to turn off the A/C clutch depressed to the floor, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.
Here's how to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.
WARNING!!! There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.
What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems. This is crucial: the same wire that provides the ground to dump the codes provides signal ground for the TPS, EGR, ACT and Map/Baro sensors. If it fails, you will have poor performance, economy and drivability problems
Some codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off, clutch depressed to the floor and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
Cylinder balance test
If you have idle or IAC/IAB problems and the engine will not idle on its own without mechanically adjusting the base idle speed above 625-750 RPM, this test will fail with random cylinders pointed out every time it runs. The IAC/IAB must be capable of controlling the engine speed to run in the 1400-1600 RPM range. Playing with the base idle speed by adjusting it upwards will not work, the computer has to be able to control the engine speed using the IAC/IAB.
Warm the car's engine up to normal operating temperature. Use a jumper wire or paper clip to put the computer into test mode. Let it finish the Key On Engine Off (KOEO) code dump. Start the engine and let it go through the normal diagnostic tests, then quickly press the throttle to the floor. Remember to keep the clutch pedal (5 speed) depressed to the floor during the test. The engine RPM should exceed 2500 RPM's for a brief second. The engine RPM's will increase to about 1450-1600 RPM and hold steady. The engine will shut off power to each injector, one at a time. When it has sequenced through all 8 injectors, it will flash 9 for everything OK, or the number of the failing cylinder such as 2 for cylinder #2. Quickly pressing the throttle again up to 2500 RPM’s will cause the test to re-run with smaller qualifying figures.
Do it a third time, and if the same cylinder shows up, the cylinder is weak and isn’t putting out power like it should. See the Chilton’s Shop manual for the complete test procedure
Do a compression test on all the cylinders.
Take special note of any cylinder that shows up as weak in the cylinder balance test. Low compression on one of these cylinders rules out the injectors as being the most likely cause of the problem. Look at cylinders that fail the cylinder balance test but have good compression. These cylinders either have a bad injector, bad spark plug or spark plug wire. Move the wire and then the spark plug to another cylinder and run the cylinder balance test again. If it follows the moved wire or spark plug, you have found the problem. If the same cylinder fails the test again, the injector is bad. If different cylinders fail the cylinder balance test, you have ignition problems or wiring problems in the 10 pin black & white electrical connectors located by the EGR.
How to do a compression test:
Only use a compression tester with a screw in adapter for the spark plug hole. The other type leaks too much to get an accurate reading. Your local auto parts store may have a compression tester to rent. If you do mechanic work on your own car on a regular basis, it would be a good tool to add to your collection.
With the engine warmed up, remove all spark plugs and prop the throttle wide open, crank the engine until it the gage reading stops increasing. On a cold engine, it will be hard to tell what's good & what's not. Some of the recent posts have numbers ranging from 140-170 psi. If the compression is low, squirt some oil in the cylinder and do it again – if it comes up, the rings are worn. There should be no more than 10% difference between cylinders. Use a blow down leak test (puts compressed air inside cylinders) on cylinders that have more than 10% difference.
See the link to my site for details on how to build your own blow down type compression tester.
I couldnt get any of the engine stuff worked out this week, so im getting geared up to do it this coming up week. I have a digital voltmeter, now when dumping the codes, what should I be looking for or what setting should I have it on?
And the "grey self test input connecter", thats the grey thing behind the main diagnostic connector?
And the "grey self test input connecter", thats the grey thing behind the main diagnostic connector?
Yes it is the Grey connector. Be sure it has a white/red wire attatched to it. Do not mistake it for the connector for the hood lamp, 12v power will kill the pcm.
A test light is easier than a volt meter, set your multimeter on a low dc voltage setting. ie.. 20vdc
A test light is easier than a volt meter, set your multimeter on a low dc voltage setting. ie.. 20vdc
Thanks, ill just pick up the light jrichker posted, easier to count light flashes anyways
**EDIT**
I forgot to say that i was talking to a guy at a local tune up shop (max rpm), about electrical diagnostics on th car, and he mentioned something about mt a9l ECU not being chipped to handle the injectors that I have, but i have the calibrated MAF - So... idk if that holds any weight
Alright, finally got around to working on her, and with the help of a fellow stangnet founder and his wonderful OBD1 reader, here are the codes we got from it -
66 - KOEO - TOT sensor output was less than self test minimum value of .15
From CPU Memory - MAF sensor went below 0.4 volts in its last 80 warm up cycles
81 - KOEO - Air managment 2 circuit failure (no smog stuff on the car)
From CPU Memory - MAP sensor vaccum was not greater than 2 in -hg during normal vehichle opperation
82 - KOER - Air managment 1 circuit failure (no smog stuff on the car)
88 - KOEO - Electro drive fan circuit failure (but I have a stock cluch fan)
From CPU Memory - Loss of dual plug input control (does not sound good)
95 - KOEO and CPU Memory - Fuel pump secondary circuit failure. The EEC senses infinate resistance to ground from the fuel pump on the fuel pump monitor circuit (a new fuel pump was installed, not by me though)
98 - KOER - Hard Fault Present (this really does not sound good)
I know that a few of those are emmisions errors, which will never go away as that has all been removed from the car. IIRC, code 98 means that a sensor is failing, but it does not distinguish which sensor...
I cleaned out the IAC with TB cleaner, and let me tell you, there was a WHOLE lot of gunk in there, im going to pour some Lucas fuel injector cleaner in there for good measure, and as long as it dosent come out too black, re use it and put it in with the rest of bottle.
I also picked up a set of 18# stock injectors and MAF to replace the 30#'ers I have on there right now.
Also found out that my PCV valve had blown out, so it was open to the atmosphere, as well as the BAP, which I had purpousfly blocked off from the intake side, as I was told to do this in a previous post. I reconnected that vaccum hose from the upper intake back into the MAP, and no adverse side effects like I had before
With the IAC cleaned (before Lucas), BAP reconnected to the MAP, and adjusted my TPS, the car runs WAY better than it did before. My idle, which used to flux between 700 - 900 is now STEADY at 900, right where I want it, as well as the HANGING IDLE problem I had, where the car would hang at 2000RPM and slowly work its way down (this used to happen on start up, AND putting the car into neutral to coast)
So it seems that things are looking up. I picked up Duralast SU203 Temp sensor that im going to install after I take the upper intake off to take out the 30#ers and place the stock ones back in.
BUT as far as the codes go, what are your guys's thoughts?
66 - KOEO - TOT sensor output was less than self test minimum value of .15
From CPU Memory - MAF sensor went below 0.4 volts in its last 80 warm up cycles
81 - KOEO - Air managment 2 circuit failure (no smog stuff on the car)
From CPU Memory - MAP sensor vaccum was not greater than 2 in -hg during normal vehichle opperation
82 - KOER - Air managment 1 circuit failure (no smog stuff on the car)
88 - KOEO - Electro drive fan circuit failure (but I have a stock cluch fan)
From CPU Memory - Loss of dual plug input control (does not sound good)
95 - KOEO and CPU Memory - Fuel pump secondary circuit failure. The EEC senses infinate resistance to ground from the fuel pump on the fuel pump monitor circuit (a new fuel pump was installed, not by me though)
98 - KOER - Hard Fault Present (this really does not sound good)
I know that a few of those are emmisions errors, which will never go away as that has all been removed from the car. IIRC, code 98 means that a sensor is failing, but it does not distinguish which sensor...
I cleaned out the IAC with TB cleaner, and let me tell you, there was a WHOLE lot of gunk in there, im going to pour some Lucas fuel injector cleaner in there for good measure, and as long as it dosent come out too black, re use it and put it in with the rest of bottle.
I also picked up a set of 18# stock injectors and MAF to replace the 30#'ers I have on there right now.
Also found out that my PCV valve had blown out, so it was open to the atmosphere, as well as the BAP, which I had purpousfly blocked off from the intake side, as I was told to do this in a previous post. I reconnected that vaccum hose from the upper intake back into the MAP, and no adverse side effects like I had before
With the IAC cleaned (before Lucas), BAP reconnected to the MAP, and adjusted my TPS, the car runs WAY better than it did before. My idle, which used to flux between 700 - 900 is now STEADY at 900, right where I want it, as well as the HANGING IDLE problem I had, where the car would hang at 2000RPM and slowly work its way down (this used to happen on start up, AND putting the car into neutral to coast)
So it seems that things are looking up. I picked up Duralast SU203 Temp sensor that im going to install after I take the upper intake off to take out the 30#ers and place the stock ones back in.
BUT as far as the codes go, what are your guys's thoughts?
MAP/Baro sensor
On a Speed Density car, the MAP/BARO sensor is connected to the intake manifold and acts to sense the manifold pressure. Lower vacuum inside the intake manifold when combined with more throttle opening measured by the TPS means more airflow through the engine. As airflow increases, fuel flow through the injectors needs to increase to keep the air/fuel ratio where it needs to be. When manifold vacuum increases, the engine is either decelerating or idling, and it needs to reduce the fuel flow through the injectors.
On a Mass Air car, the MAP/BARO sensor vents to open air and actually senses the barometric pressure due to changes in weather and altitude. Its purpose is to set a baseline for the computer to know the barometric pressure. As barometric pressure decreases, it leans out the fuel flow to compensate for less oxygen in the air. When the barometric pressure rises, it increases to add fuel since there is more oxygen in the air. The fuel requirements decrease as altitude increases, since the atmospheric pressure decreases.
Code 66 MAF below minimum test voltage.
Insufficient or no voltage from MAF. Dirty MAF element, bad MAF, bad MAF wiring, missing power to MAF. Check for missing +12 volts on this circuit. Check the two links for a wiring diagram to help you find the red wire for computer power relay switched +12 volts. Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF. This may require the use of a couple of safety pins to probe the MAF connector from the back side of it.
There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables.
The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).
Changes in RPM causes the airflow to increase or decease, changing the voltage output.. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow.
Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.
At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt
Check the resistance of the MAF signal wiring. Pin D on the MAF and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.
There should be a minimum of 10K ohms between either pin C or D on the MAF wiring connector and pins A or B. Make your measurement with the MAF disconnected from the wiring harness.
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/
Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif
Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif
Computer,. actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif
Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif
Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
Code 98 - basic computer internal tests not passed before it started processing the request to dump codes. Do a Key On Engine Off test before starting the engine. Wait until you see the 11 flash before pressing any buttons if you have a hand operated scanner. The computer is operating in Limp mode, so fix any codes it dumps prior to doing anything else.
On a Speed Density car, the MAP/BARO sensor is connected to the intake manifold and acts to sense the manifold pressure. Lower vacuum inside the intake manifold when combined with more throttle opening measured by the TPS means more airflow through the engine. As airflow increases, fuel flow through the injectors needs to increase to keep the air/fuel ratio where it needs to be. When manifold vacuum increases, the engine is either decelerating or idling, and it needs to reduce the fuel flow through the injectors.
On a Mass Air car, the MAP/BARO sensor vents to open air and actually senses the barometric pressure due to changes in weather and altitude. Its purpose is to set a baseline for the computer to know the barometric pressure. As barometric pressure decreases, it leans out the fuel flow to compensate for less oxygen in the air. When the barometric pressure rises, it increases to add fuel since there is more oxygen in the air. The fuel requirements decrease as altitude increases, since the atmospheric pressure decreases.
Code 66 MAF below minimum test voltage.
Insufficient or no voltage from MAF. Dirty MAF element, bad MAF, bad MAF wiring, missing power to MAF. Check for missing +12 volts on this circuit. Check the two links for a wiring diagram to help you find the red wire for computer power relay switched +12 volts. Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF. This may require the use of a couple of safety pins to probe the MAF connector from the back side of it.
There are three parts in a MAF: the heater, the sensor element and the amplifier. The heater heats the MAF sensor element causing the resistance to increase. The amplifier buffers the MAF output signal and has a resistor that is laser trimmed to provide an output range compatible with the computer's load tables.
The MAF element is secured by 2 screws & has 1 wiring connector. To clean the element, remove it from the MAF housing and spray it down with electronic parts cleaner or non-inflammable brake parts cleaner (same stuff in a bigger can and cheaper too).
Changes in RPM causes the airflow to increase or decease, changing the voltage output.. The increase of air across the MAF sensor element causes it to cool, allowing more voltage to pass and telling the computer to increase the fuel flow. A decrease in airflow causes the MAF sensor element to get warmer, decreasing the voltage and reducing the fuel flow.
Measure the MAF output at pins C & D on the MAF connector (dark blue/orange and tan/light blue) or at pins 50 & 9 on the computer. Be sure to measure the sensor output by measuring across the pins and not between the pins and ground.
At idle = approximately .6 volt
20 MPH = approximately 1.10 volt
40 MPH = approximately 1.70 volt
60 MPH = approximately 2.10 volt
Check the resistance of the MAF signal wiring. Pin D on the MAF and pin 50 on the computer (dark blue/orange wire) should be less than 2 ohms. Pin C on the MAF and pin 9 on the computer (tan/light blue wire) should be less than 2 ohms.
There should be a minimum of 10K ohms between either pin C or D on the MAF wiring connector and pins A or B. Make your measurement with the MAF disconnected from the wiring harness.
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/
Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif
Fuel pump, alternator, ignition & A/C wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif
Computer,. actuator & sensor wiring
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif
Fuse panel layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif
Vacuum routing
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
Code 98 - basic computer internal tests not passed before it started processing the request to dump codes. Do a Key On Engine Off test before starting the engine. Wait until you see the 11 flash before pressing any buttons if you have a hand operated scanner. The computer is operating in Limp mode, so fix any codes it dumps prior to doing anything else.
Yes, this is correct. I did uncork the hose coming out of the back of the upper, and hooked it back up to the MAP per his instruction (and he has 3 MAF stangs and a LTD wagon he dropped a stang motor in) He tested the MAP sensor, and it checked out just fine. And im wondering if this is a good thing for now, due to the code 66, because when I brought the car into his shop, he could tell instantly that it was running way too rich, and now that the BAP is hooked back up, it doesnt quite smell so bad, and still runs fine, but am I in danger of running lean by doing this?.
Once I get my stock MAF and stock 18#ers put back in (should be tuesday coming up) ill disconnect it as it should be (after checking MAF wiring harness).
As far as the code 98 goes, I told my friend that it should read a code 11 at some point before we start the engine, and he said no, code 11 is an all clear code, and would not be seen until the other KOEO codes are cleared - now I trust my fellow stangnet brother, as he is known as the 5.0 guru around these parts, but hes only available 2 days a week, so I will talk to him and see what else we can do, and by that time, id have switched back to my stock injectors, stock MAF, and done my voltmeter testing for the MAF wiring.
Code 88 and Code 95 - Does anyone know what these mean?
"Code 66 MAF below minimum test voltage.
Insufficient or no voltage from MAF - Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF."
So I just went out on my break, took 2 T pins and peirced the red and black wires (which are VERY small gauge wires for some reason) that come out of the MAF harness where it plugs into the MAF itself (had to kind if peel/move the cover that covers those wires to access them), and I am getting 0 volts. I tried this with the car running, and the car not running.
I also tested the dark blue / orange and tan / light blue together, and also got 0 volts at idle...
Insufficient or no voltage from MAF - Check for 12 volts between the red and black wires on the MAF heater (usually pins A & B). while the connector is plugged into the MAF."
So I just went out on my break, took 2 T pins and peirced the red and black wires (which are VERY small gauge wires for some reason) that come out of the MAF harness where it plugs into the MAF itself (had to kind if peel/move the cover that covers those wires to access them), and I am getting 0 volts. I tried this with the car running, and the car not running.
I also tested the dark blue / orange and tan / light blue together, and also got 0 volts at idle...
Since your car is an 86, and did not come from the factory with Mass Air, someone had to convert or attempt to convert it to Mass Air. It is entirely possible that the harness was installed but it never got a matching Mass Air computer.
Remove the passenger side kick panel and remove the two screws from the plastic computer mount strap. Pull the computer down so that you can see the sticker on it. Check the number sticker on the end opposite the wiring connector for one of the numbers on the cart below.
Mass Air computers and harness information
Revised 16-Oct-2011 to add O2 sensor harness warnings
The Mass Air computers from 89-93 are interchangeable with a few exceptions. Just be sure you use the MAF & MAF sensor from the same series computer. The auto transmission computers use a different start circuit than the manual computers. You can use an auto trans computer in a 5 speed car with no problems or changes. I have done it in my original 89 Mustang GT, and I know it works OK. I would recommend avoiding using a 5 speed computer in an auto trans car due to the possibility of damaging the computer’ internal signal ground circuitry.
The odd duck is the 93 Cobra computer, labeled X3Z which is internally calibrated for 24 lb injectors. Use the MAF & MAF sensor from the X3Z computer to avoid problems with the computer's internal calibration. Try and avoid the 93 Cobra computer if you can.
Some cautions about O2 Sensor harnesses need to be observed to avoid damage to the computer.
Only run a 5 speed trans O2 harness with an A9L. Do not run an Auto O2 sensor harness with an A9L. Doing so will damage the computer’s internal signal ground.
Only run an Auto trans O2 sensor harness with an A9P in a car that has an Auto trans. Using a 5 speed trans O2 sensor harness with an Auto trans will cause no crank problems.
See http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor- harnesses-manual-auto-differences-year-differences.html for more O2 sensor wiring harness info
If you have a damaged computer with signal ground problems, See http://www.stangnet.com/mustang-forums/749974-computer-issue.html#post7490537 for Joel5.0’s fix to the computer internal signal ground.
All the following are mass air unless they say Speed Density
8LD - MANUAL 88 5.0L Mustang Mass Air - California
8LF - Auto 88 5.0L Mustang Mass Air- California
8LG - Auto 88 5.0L Mustang Mass Air- California
A9L - 89-93 5.0L Mustang 5-spd Mass Air
A3M - 93 5.0L Mustang 5-spd Mass Air
A3M1 - 93 5.0L Mustang 5-spd Mass Air
X3Z - 93 5.0L Cobra 5-spd Mass Air internally calibrated for 24 lb injector
A9P - 89-93 5.0L Mustang Auto Mass Air
A9S - 88-93 5.0L Mustang California Mass Air
C3W - 89-93 5.0L Mustang Auto
DA1 - 87 5.0L Mustang 5-spd Speed Density
J4J1 - 94-95 5.0L SVT Cobra 5-spd
T4M0 - 94-95 5.0L GT Vert 5-spd
U4P0 - 94-95 5.0L GT Auto
W4H0 - 94-95 5.0L GT
ZA0 - 95 Cobra R
D9S - 88 Lincoln LSC Speed Density
If the sticker comes up with a Mass Air computer, you get to go hunting. I hope you can read circuit diagrams well, because at this point, you’re going to get lots of practice.
MASS air conversion instructions from http://www.stangnet.com/tech/maf/massairconversion.html
Diagrams you may need...
Diagram courtesy of Tmoss & Stang&2birds
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.
Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif
Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif
Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif
Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif
Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif
TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif
Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif
87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif
93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif
Remove the passenger side kick panel and remove the two screws from the plastic computer mount strap. Pull the computer down so that you can see the sticker on it. Check the number sticker on the end opposite the wiring connector for one of the numbers on the cart below.
Mass Air computers and harness information
Revised 16-Oct-2011 to add O2 sensor harness warnings
The Mass Air computers from 89-93 are interchangeable with a few exceptions. Just be sure you use the MAF & MAF sensor from the same series computer. The auto transmission computers use a different start circuit than the manual computers. You can use an auto trans computer in a 5 speed car with no problems or changes. I have done it in my original 89 Mustang GT, and I know it works OK. I would recommend avoiding using a 5 speed computer in an auto trans car due to the possibility of damaging the computer’ internal signal ground circuitry.
The odd duck is the 93 Cobra computer, labeled X3Z which is internally calibrated for 24 lb injectors. Use the MAF & MAF sensor from the X3Z computer to avoid problems with the computer's internal calibration. Try and avoid the 93 Cobra computer if you can.
Some cautions about O2 Sensor harnesses need to be observed to avoid damage to the computer.
Only run a 5 speed trans O2 harness with an A9L. Do not run an Auto O2 sensor harness with an A9L. Doing so will damage the computer’s internal signal ground.
Only run an Auto trans O2 sensor harness with an A9P in a car that has an Auto trans. Using a 5 speed trans O2 sensor harness with an Auto trans will cause no crank problems.
See http://forums.corral.net/forums/general-mustang-tech/1094179-oxygen-sensor- harnesses-manual-auto-differences-year-differences.html for more O2 sensor wiring harness info
If you have a damaged computer with signal ground problems, See http://www.stangnet.com/mustang-forums/749974-computer-issue.html#post7490537 for Joel5.0’s fix to the computer internal signal ground.
All the following are mass air unless they say Speed Density
8LD - MANUAL 88 5.0L Mustang Mass Air - California
8LF - Auto 88 5.0L Mustang Mass Air- California
8LG - Auto 88 5.0L Mustang Mass Air- California
A9L - 89-93 5.0L Mustang 5-spd Mass Air
A3M - 93 5.0L Mustang 5-spd Mass Air
A3M1 - 93 5.0L Mustang 5-spd Mass Air
X3Z - 93 5.0L Cobra 5-spd Mass Air internally calibrated for 24 lb injector
A9P - 89-93 5.0L Mustang Auto Mass Air
A9S - 88-93 5.0L Mustang California Mass Air
C3W - 89-93 5.0L Mustang Auto
DA1 - 87 5.0L Mustang 5-spd Speed Density
J4J1 - 94-95 5.0L SVT Cobra 5-spd
T4M0 - 94-95 5.0L GT Vert 5-spd
U4P0 - 94-95 5.0L GT Auto
W4H0 - 94-95 5.0L GT
ZA0 - 95 Cobra R
D9S - 88 Lincoln LSC Speed Density
If the sticker comes up with a Mass Air computer, you get to go hunting. I hope you can read circuit diagrams well, because at this point, you’re going to get lots of practice.
MASS air conversion instructions from http://www.stangnet.com/tech/maf/massairconversion.html
Diagrams you may need...
Diagram courtesy of Tmoss & Stang&2birds
See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.
Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif
Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif
Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif
Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif
Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif
TFI module differences & pin out
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif
Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif
87-92 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang87-92 PowerWindowWiring.gif
93 power window wiring
http://www.veryuseful.com/mustang/tech/engine/images/mustang93PowerWindows.gif
Than a hunting I shall go - The computer is an A9L. After I pulled my computer the first time over a year ago to troubleshoot the absolute mess my car was (too much to go into, but can be searched for 
) , I found an ECU out of a Mercury Topaz (shop that rebuilt didnt know elbows from their ***holes). So Serjiou (fellow stangnet member) was kind enough to ship me one of his spares, its labled as A9L and it fixed the vast majority of the issues.
So since my MAF is essentially dead at the moment, and probibly has been dead for a while, would this cause any running rich/lean issues, drivbility problems, should I stop driving it, because after yesterday, pulling the codes, setting TPS within paramaters, and reconnecting the vaccum line from the upper intake to the MAP, the surging idle is gone and hanging idle is gone. Should I take the vaccum line off the MAP and re plug the line going into the upper intake?
) , I found an ECU out of a Mercury Topaz (shop that rebuilt didnt know elbows from their ***holes). So Serjiou (fellow stangnet member) was kind enough to ship me one of his spares, its labled as A9L and it fixed the vast majority of the issues.So since my MAF is essentially dead at the moment, and probibly has been dead for a while, would this cause any running rich/lean issues, drivbility problems, should I stop driving it, because after yesterday, pulling the codes, setting TPS within paramaters, and reconnecting the vaccum line from the upper intake to the MAP, the surging idle is gone and hanging idle is gone. Should I take the vaccum line off the MAP and re plug the line going into the upper intake?
Another thing im worried about is continuing to drive the car with the MAF not functioning. Could this cause damage to the car?
And ive now read mixed things regarding having the BAP hooked up to the vaccum tree under the intake. I know the difference between the 2 different configurations, but again, question being with the BAP hooked up to vaccum on a A9L mass air ECU, could this cause any sort of damage?
And ive now read mixed things regarding having the BAP hooked up to the vaccum tree under the intake. I know the difference between the 2 different configurations, but again, question being with the BAP hooked up to vaccum on a A9L mass air ECU, could this cause any sort of damage?
Hey guys - got some more info here, the ANSWER to the problem!
I took a break from looking under the hood for a few days, it was stressing me out, just had to take a step back and breathe. So unhooked the MAF connecter from the sensor and freeing it up to get some slack in the line, and saw that it was routed through the firewall thru an existing grommet. Reomved the passenger side kickpanel and unhooked ECU hold downs to bring it out in the open - and here is what i see...
That is the end of the MAF wiring harness that was connected to the MAF sensor. I was able to pull it gently from the engine bay side, and see it move up torward the firewall on the inside, and pull it back from the inside, and see the slack wire tighten inside the engine bay...
So now I need to make a decision - either remove the A9L to find a speed density ECU and hook that up and remove the MAF sensor and harness from the car -
a.) If i went this route, what other things would I need to make sure are in place
or work on splicing the MAF harness into the ECU harness, which I do have the instructions for (ty again jr)
b.) If i went this route, its obviously going to be more difficult, what advantages would I see in comparison to SD?
Just kind of taken back that it was something that simple, and should have been the first thing I checked... Is it getting power, if not, why
I took a break from looking under the hood for a few days, it was stressing me out, just had to take a step back and breathe. So unhooked the MAF connecter from the sensor and freeing it up to get some slack in the line, and saw that it was routed through the firewall thru an existing grommet. Reomved the passenger side kickpanel and unhooked ECU hold downs to bring it out in the open - and here is what i see...
That is the end of the MAF wiring harness that was connected to the MAF sensor. I was able to pull it gently from the engine bay side, and see it move up torward the firewall on the inside, and pull it back from the inside, and see the slack wire tighten inside the engine bay...
So now I need to make a decision - either remove the A9L to find a speed density ECU and hook that up and remove the MAF sensor and harness from the car -
a.) If i went this route, what other things would I need to make sure are in place
or work on splicing the MAF harness into the ECU harness, which I do have the instructions for (ty again jr)
b.) If i went this route, its obviously going to be more difficult, what advantages would I see in comparison to SD?
Just kind of taken back that it was something that simple, and should have been the first thing I checked... Is it getting power, if not, why
Car won't run right with mods like bigger injectors if you stay SD.
If I were you, I'd do the MAF conversion properly. Going mass air flow will allow you to throw plenty of mods at it and it'll compensate for the increased airflow going into the engine. SD absolutely sucks when modding unless you have a dyno in your own garage and you're good at tuning. But for the regular Joe, spending time wiring up a MAF conversion is completely worth it.
If I were you, I'd do the MAF conversion properly. Going mass air flow will allow you to throw plenty of mods at it and it'll compensate for the increased airflow going into the engine. SD absolutely sucks when modding unless you have a dyno in your own garage and you're good at tuning. But for the regular Joe, spending time wiring up a MAF conversion is completely worth it.
Yea thats what I have been reading, so ill be doing that at some point before the end of the year. Ive been racking my brain trying to figure out why someone would put an actuall male adapter on the end of the harness unless it was connected to something at some point in time, but ive looked all over my ECUs wiring harness, and there is no female 4 pin adapter to plug it in to...
I have a few questions as im digging into this - see picture below
First question is - the wire that is branching off of the main harness and grounding to the frame- there is the blue looking connector with a wire cut off (to the right of the ending of the MAF connector), Im pretty sure that this is the ECU ground, but I do not know what was or was suposed to be spliced into this ground
Second question is - to the right of that blue connector, is what looks to be a vaccum line? Does anyone know what this wire is for? it is also mounted through the firewall, but cannot locate its end point, but I dont see anywhere to hook it up to, and dont know what a vac line would be doing inside the firewall of the car
Thanks guys
First question is - the wire that is branching off of the main harness and grounding to the frame- there is the blue looking connector with a wire cut off (to the right of the ending of the MAF connector), Im pretty sure that this is the ECU ground, but I do not know what was or was suposed to be spliced into this ground
Second question is - to the right of that blue connector, is what looks to be a vaccum line? Does anyone know what this wire is for? it is also mounted through the firewall, but cannot locate its end point, but I dont see anywhere to hook it up to, and dont know what a vac line would be doing inside the firewall of the car
Thanks guys
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