Engine Dies When Clutch Is Engaged (not Stalling....)

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by fnl388w, Nov 5, 2013.


  1. fnl388w

    fnl388w New Member

    Joined:
    May 15, 2006
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    2
    Location:
    Columbus, IN
    Hello Everyone!

    I am in need of some help... my '93 hatchback has a new engine ('90 5.0) and T5 trans ('92). Both are completely stock. I have the engine running (YEAH!) and it idles all day long... as long as I have the clutch pedal pushed in (clutch disengaged). When I let the pedal out (engage the clutch) to let it idle, with the trans in neutral, the car dies. It shuts off like you turned the key off (it is NOT stalling, just want to clarify).

    Now it gets interesting...

    If I rev the engine to around 2K and let the clutch pedal out (engage the clutch), it runs smooth as silk, but once I let it drop back to idle, it dies again. I just replaced the speed sensor plug, next to the speedo cable in the trans. I read somewhere that these can go bad and cause the car to stall when coming to a stop. Did nothing.
    I don't know what to do! I'm going crazy trying to figure it out.:drink:

    Has anyone out there had any similar issues? I'm open to any and all ideas.
     
    #1
  2. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,822
    Likes Received:
    403
    Trophy Points:
    134
    Location:
    Dublin GA
    Dump the codes: Codes may be present even if the Check Engine Light (CEL) isn't on.

    Dumping the computer diagnostic codes on 86-95 Mustangs

    Revised 26-July-2011. Added need to make sure the clutch is pressed when dumping codes.

    Codes may be present even if the check engine light hasn’t come on, so be sure to check for them.

    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.

    Post the codes you get and I will post 86-93 model 5.0 Mustang specific code definitions and fixes. I do not have a complete listing for 94-95 model 5.0 Mustangs at this time.

    Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. On a manual transmission car, be sure to press the clutch to the floor.
    Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.

    [​IMG]

    [​IMG]

    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.

    [​IMG]

    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.

    [​IMG]

    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 driveablity 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, and clutch (if present) is pressed 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.

    Your 86-88 5.0 won't have a working Check Engine Light, so you'll need a test light.
    See AutoZone Part Number: 25886 , $10
    [​IMG]



    Alternate methods:
    For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

    Or for a nicer scanner see www.midwayautosupply.com/Equus-Digital-Ford-Code-Reader/dp/B000EW0KHW Equus - Digital Ford Code Reader (3145It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $22-$36.
     
    #2
  3. 90lxwhite

    90lxwhite I'm kind of a She-Man

    Joined:
    Aug 25, 2011
    Messages:
    2,452
    Likes Received:
    281
    Trophy Points:
    104
    Location:
    Between the Red and Rio
    Hey J, do you have to post that sticky every time or does it do it for you automatically?
     
    #3
  4. 91TwighlightGT

    91TwighlightGT Active Member

    Joined:
    Sep 9, 2002
    Messages:
    592
    Likes Received:
    93
    Trophy Points:
    39
    Location:
    Missouri
    It isn't a bad way to start the thread, since any diagnosis such as this is made far easier by having DTC's.
     
    #4
  5. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,822
    Likes Received:
    403
    Trophy Points:
    134
    Location:
    Dublin GA
    Look at my post count and the number of years I have been posting on Stangnet. The Dump the codes post makes up a good portion of it. Most people don't know that the computer self diagnoses the system, or how to dump the codes. It is THE best place to start when you are having engine problems with an EFI 5.0 Mustang. It is cheaper and much more cost and time efficient to diagnose a problem than to throw parts, time and money at it.

    Since you haven't been beaten with this stick, I'll get it out and point it in your direction...

    Sir Joshua Reynolds' famous quotation: "There is no expedient to which a man will not resort to avoid the real labor of thinking."

    Good troubleshooting takes time. Everyone seems to be looking for the magic tip that says replace this $13 part and your problems are cured. You don't have to think, dig or diagnose, just buy the part and install it. Unfortunately, it doesn’t work that way 99% of the time.
    Thinking is hard work and educated thinking requires much more effort than simple parts swapping. The complexity and age of these 5.0 Mustangs works against that, as well as the number of hands that have “modified” the original design. Sometimes that modification is well done with good workmanship and other times it is mechanical road kill. It is very easy to become the victim of the previous owner’s efforts.

    I spend a great deal of time trying to communicate the methodology of structured troubleshooting principles. For those who haven’t been beaten with this stick before, here they are again:

    1.) Understand the system. That involves reading some books to get an overall picture of how it works. For 5.0 Mustangs, that list starts with the Chilton shop manual and the Probst book, Ford Fuel Injection & Electronic Engine Control 1988-1993 by Charles Probst :ISBN 0-8376-0301-3. It's about $30-$40 from Borders.com, see
    http://www.amazon.com. Select books and then select search. Use the ISBN number (without dashes or spaces) to do a search. Use the ISBN number and your local library can get you a loaner copy for free for 2 weeks or so.

    For free automotive electrical training, see http://www.autoshop101.com/ . I have personally reviewed the material and it is very good.

    Another resource is the following website by Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring: http://www.veryuseful.com/mustang/tech/engine. Study the diagrams and tech articles. There is an amazing amount of good stuff in one place for FREE.

    2.) Isolate the problem. You need to be able to break the system down into functional blocks or subsystems. Once you know what subsystem has failed, it is much easier to troubleshoot. Group problem symptoms according to what system controls them. Don’t look for a fix for ignition problems by adjusting the fuel pressure. Have an organized, step by step, approach to work your way through a subsystem before you quit and go off wildly chasing rabbits. You have three tools to use in your efforts:[ : measure, observe and think!. Use these three tools to narrow down the list of possible failure points into a small, easily managed list of items.

    3.) Install the fix. Now that you have a short list of suspected villains, plan your repair efforts so that you do the easy things first. If an item from the easy list didn’t fix your problem, then look at the high failure rate items. Spend some time here on Stangnet and you’ll get an idea of what the most commonly replaced parts are, things like TFI modules, ignition switches and fuel pump relays.

    If you make a change and it doesn’t relieve the problem symptoms, put it back the way it was. I have a stack of parts from where I swapped a part and it didn’t fix the problem. I put the old part back on the car and the new part went on the shelf. Someday I will either use them or trade them for something else.
     
    #5
    Last edited: Nov 7, 2013
    A5literMan likes this.
  6. fnl388w

    fnl388w New Member

    Joined:
    May 15, 2006
    Messages:
    2
    Likes Received:
    0
    Trophy Points:
    2
    Location:
    Columbus, IN
    Ok, I think I counted right. I did it 3 times just to triple check.

    Here are the consistent ones that I read:

    21
    22
    23
    67
    31
    51
    53
    54

    And possibly 11

    I have removed the smog pump, but the connection (round with vacuum line running out either side) is still connected. It is plugged after the connection.

    So.... What are my issues? :D
     
    #6
  7. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,822
    Likes Received:
    403
    Trophy Points:
    134
    Location:
    Dublin GA
    Sorry this has taken so long. I have been away from reliable Internet connection for some time.


    Fix the code 22 first.
    Some of the other codes look like a possible bad signal ground for the engine mounted sensors.

    Code 21 – ECT sensor out of range. Broken or damaged wiring, bad ECT sensor.
    Note that that if the outside air temp is below 50 degrees F that the test for the ECT can be in error. Warm the engine up until you get good hot air from the heater and then dump the codes again.

    The ECT sensor has absolutely nothing to do with the temperature gauge. They are different animals. The ECT sensor is normally located it the passenger side front of the engine in the water feed tubes for the heater.

    The ACT & ECT have the same thermistor, so the table values are the same

    ACT & ECT test data:

    Use Pin 46 on the computer for ground for both ECT & ACT to get most accurate readings.

    Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

    Pin 25 on the computer - ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer.

    [​IMG]

    Voltages may be measured across the ECT/ACT by probing the connector from the rear. A pair of safety pins may be helpful in doing this. Use care in doing it so that you don't damage the wiring or connector.

    Here's the table :

    50 degrees F = 3.52 v
    68 degrees F = 3.02 v
    86 degrees F = 2.62 v
    104 degrees F = 2.16 v
    122 degrees F = 1.72 v
    140 degrees F = 1.35 v
    158 degrees F = 1.04 v
    176 degrees F = .80 v
    194 degrees F = .61
    212 degrees F = .47 v
    230 degrees F = .36 v
    248 degrees F = .28 v

    Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.

    50 degrees F = 58.75 K ohms
    68 degrees F = 37.30 K ohms
    86 degrees F = 27.27 K ohms
    104 degrees F = 16.15 K ohms
    122 degrees F = 10.97 K ohms
    140 degrees F = 7.60 K ohms
    158 degrees F = 5.37 K ohms
    176 degrees F = 3.84 K ohms
    194 degrees F = 2.80 K ohms
    212 degrees F = 2.07 K ohms
    230 degrees F = 1.55 K ohms
    248 degrees F = 1.18 k ohms

    Diagram courtesy of Tmoss & Stang&2birds

    [​IMG]



    MAP/BARO sensor operation and code 22

    Revised 19-Jul-2011 to add functional descriptions for MAP and BARO operation.

    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.

    Disconnecting the MAP or BARO sensor will set code 22.

    Misconnecting the BARO sensor to vacuum on a Mass Air car will cause the computer to lean out the fuel mixture.

    Code 22 or 126 MAP (vacuum) or BARO signal out of range. The MAP or BARO sensor is pretty much the same sensor for both Mass Air & Speed Density cars. The main difference is where it is connected. Mass Air cars vent it to the atmosphere, while Speed Density cars connect it to the intake manifold vacuum. Its purpose is to help set a baseline for the air/fuel mixture by sensing changes in barometric pressure. The MAP or BAP sensor puts out a 5 volt square wave that changes frequency with variations in atmospheric pressure. The base is 154 HZ at 29.92" of mercury - dry sunny day at sea level, about 68-72 degrees. You need an oscilloscope or frequency meter to measure it. There a very few DVM’s with a price tag under $40 that will measure frequency, but there are some out there.

    The MAP/BARO sensor is mounted on the firewall behind the upper manifold on 86-93 Mustangs.

    Baro or MAP test using a real frequency meter - run the test key on, engine off. The noise from the ignition system will likely upset the frequency meter. I used a 10 x oscilloscope probe connected from the frequency meter to the MAP/BAP to reduce the jitter in the meter's readout. And oscilloscope is very useful if you have access to one or know of someone who does. With an oscilloscope, you can see the waveform and amplitude.

    If it is defective, your air/fuel ratio will be off and the car’s performance & emissions will suffer

    Some basic checks you can make to be sure that the sensor is getting power & ground:
    Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter.
    Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same wire on the TPS. It should be less than 1 ohm. Next check the resistance between the black/white wire and the negative battery cable. It should be less than 1.5 ohm.

    The following power on check requires you to turn the ignition switch to the Run position.
    Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or EGR sensors. Use the black/white wire for the ground for the DVM.


    Code 23 - Throttle sensor out of range or throttle set too high - TPS needs to be reset to below 1.2 volts at idle. Keep in mind that when you turn the idle screw to set the idle speed, you change the TPS setting.
    You'll need a Digital Voltmeter (DVM) to do the job.

    Wire colors & functions:
    Orange/white = 5 volt VREF from the computer
    Dark Green/lt green = TPS output to computer
    Black/white = Signal ground from computer

    Always use the Dark Green/lt green & Black/white wires to set the TPS base voltage.

    Do the test with the ignition switch in the Run position without the engine running.

    Use the Orange/white & Black white wires to verify the TPS has the correct 5 volts source from the computer.

    When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .6.v-.9 v.

    1. Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

    2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

    If setting the TPS doesn’t fix the problem, then you may have wiring problems.
    With the power off, measure the resistance between the black/white wire and battery ground. You should see less than 2 ohms. Check the same black /white wire on the TPS and MAP/Baro sensor. More than 1 ohm there and the wire is probably broken in the harness between the engine and the computer. The 10 pin connectors pass the black/white wire back to the computer, and can cause problems.

    See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

    http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

    See http://fordfuelinjection.com/index.php?p=6 for more wiring help & 10 pin connector diagrams

    Code 67 –
    Revised 2 Nov 2012 to add definition of the NSS functions for both 5 speed and auto transmissions

    Cause of problem:
    clutch not depressed (5 speed) or car not in neutral or park (auto) or A/C in On position when codes where dumped. Possible neutral safety switch or wiring problem. This code may prevent you from running the Key On Engine On tests.

    External evidence from other sources claims that a code 67 can cause an idle surge condition. Do try to find and fix any issues with the switch and wiring if you get a code 67.

    What the NSS (Neutral Safety Switch) does:
    5 speed transmission: It has no connection with the starter, and the engine can be cranked without it being connected.
    Auto transmission: It is the safety interlock that prevents the starter from cranking the engine with the transmission in gear.
    What it does for both 5 speed and auto transmission cars:
    The computer wants to make sure the A/C is off due to the added load on the engine for the engine running computer diagnostic tests. It also checks to see that the transmission is in Neutral (5 speed and auto transmission) and the clutch depressed (T5, T56, Tremec 3550 & TKO)). This prevents the diagnostics from being run when the car is driven. Key On Engine Running test mode takes the throttle control away from the driver for several tests. This could prove hazardous if the computer was jumpered into test mode and then driven.

    The following is for 5 speed cars only.
    The NSS code 67 can be bypassed for testing. You will need to temporarily ground computer pin 30 to the chassis. Computer pin 30 uses a Lt blue/yellow wire. Remove the passenger side kick panel and then remove the plastic cover from the computer wiring connector. Use a safety pin to probe the connector from the rear. Jumper the safety pin to the ground near the computer.
    Be sure to remove the jumper BEFORE attempting to drive the car!!!

    [​IMG]

    Code 51 Engine Coolant Temperature (ECT) sensor signal is/was too high -
    Possible bad ECT sensor, or wiring. Possible missing signal ground –
    black/wire broken or bad connection. With the power off, measure the
    resistance between the black/white wire and battery ground. You should see
    less than 1 ohm. Check the same black /white wire on the TPS and MAP
    sensor. More than 1 ohm there and the wire is probably broken in the harness
    between the engine and the computer. The 10 pin connectors pass the
    black/white wire back to the computer, and can cause problems.

    The ECT sensor is not the same as the temp sender for the temp gauge. It is located in the front part of the tubing that feeds coolant to the heater. It has two wires connected to it.

    Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

    Voltages may be measured across the ECT by probing the connector from the rear.
    Use care in doing it so that you don't damage the wiring or connector.

    50 degrees F = 3.52 v
    68 degrees F = 3.02 v
    86 degrees F = 2.62 v
    104 degrees F = 2.16 v
    122 degrees F = 1.72 v
    140 degrees F = 1.35 v
    158 degrees F = 1.04 v
    176 degrees F = .80 v
    194 degrees F = .61
    212 degrees F = .47 v
    230 degrees F = .36 v
    248 degrees F = .28 v

    Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.

    50 degrees F = 58.75 K ohms
    68 degrees F = 37.30 K ohms
    86 degrees F = 27.27 K ohms
    104 degrees F = 16.15 K ohms
    122 degrees F = 10.97 K ohms
    140 degrees F = 7.60 K ohms
    158 degrees F = 5.37 K ohms
    176 degrees F = 3.84 K ohms
    194 degrees F = 2.80 K ohms
    212 degrees F = 2.07 K ohms
    230 degrees F = 1.55 K ohms
    248 degrees F = 1.18 k ohms

    Diagram courtesy of Tmoss & Stang&2birds

    [​IMG]

    Code 53 - Throttle Position sensor too high – TPS – TPS out of adjustment, bad connections, missing signal ground, bad sensor.

    Wire colors & functions:
    Orange/white = 5 volt VREF from the computer
    Dark Green/lt green = TPS output to computer
    Black/white = Signal ground from computer

    Always use the Dark green/lt green & Black/white wires to set the TPS base voltage.

    Do the test with the ignition switch in the Run position without the engine running.

    Use the Orange/white & Black white wires to verify the TPS has the correct 5 volts source from the computer.

    Setting the TPS: you'll need a good Digital Voltmeter (DVM) to do the job. Set the TPS voltage at .5- 1.1 range. Because of the variables involved with the tolerances of both computer and DVM, I would shoot for somewhere between .6 and 1.0 volts. Unless you have a Fluke or other high grade DVM, the second digit past the decimal point on cheap DVM’s is probably fantasy. Since the computer zeros out the TPS voltage every time it powers up, playing with the settings isn't an effective aid to performance or drivability. The main purpose of checking the TPS is to make sure it isn't way out of range and causing problems.

    The Orange/White wire is the VREF 5 volts from the computer. You use the Dark Green/Lt green wire (TPS signal) and the Black/White wire (TPS ground) to set the TPS. Use a pair of safety pins to probe the TPS connector from the rear of the connector. You may find it a little difficult to make a good connection, but keep trying. Put the safety pins in the Dark Green/Lt green wire and Black/White wire. Make sure the ignition switch is in the Run position but the engine isn't running.

    Here’s a TPS tip I got from NoGo50

    When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks.

    (copied from MustangMax, Glendale AZ)

    A.) Always adjust the TPS and Idle with the engine at operating temp. Dive it around for a bit if you can and get it nice and warm.

    B.) When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground.

    C.) Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

    D.) The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.

    The TPS is a variable resistor, must like the volume control knob on a cheap radio. We have all heard them crackle and pop when the volume is adjusted. The TPS sensor has the same problem: wear on the resistor element makes places that create electrical noise. This electrical noise confuses the computer, because it expects to see a smooth increase or decrease as the throttle is opened or closed.

    TPS testing: most of the time a failed TPS will set code 23 or 63, but not always. Use either an analog meter or a DVM with an analog bar graph and connect the leads as instructed above. Turn the ignition switch to the Run position, but do not start the engine. Note the voltage with the throttle closed. Slowly open the throttle and watch the voltage increase smoothly, slowly close the throttle and watch the voltage decrease smoothly. If the voltage jumps around and isn’t smooth, the TPS has some worn places in the resistor element. When the throttle is closed, make sure that the voltage is the same as what it was when you started. If it varies more than 10%, the TPS is suspect of being worn in the idle range of its travel.

    Adjusting the TPS fails to resolve the problem:
    Check the black/white wire resistance. Connect one ohmmeter lead to the black/white wire on the TPS and one lead to the negative post on the battery. You should see less than 1.5 ohm, more than that indicates a problem. Always take resistance measurements with the circuit powered off.

    Clean the 10 pin salt & pepper shaker connectors.
    [​IMG].

    See http://fordfuelinjection.com/index.php?p=85 for more help

    Code 54 – ACT sensor out of range. Broken or damaged wiring, bad ACT sensor. Note that that if the outside air temp is below 50 degrees F that the test for the ACT can be in error.

    Check the resistance of the black/white wire to battery ground. If it is less than 2 ohms, it is good. If it is more than 2 ohms, the black/white wire has bad connections or a broken wire. Always take resistance measurements with the circuit powered off.

    Then check the resistance of the ACT sender located in the #5 intake runner on most 5.0 stangs.

    ACT & ECT test data:

    The ACT & ECT have the same thermistor, so the table values are the same

    Pin 7 on the computer - ECT signal in. at 176 degrees F it should be .80 volts

    Pin 25 on the computer - ACT signal in. at 50 degrees F it should be 3.5 volts. It is a good number if the ACT is mounted in the inlet airbox. If it is mounted in the lower intake manifold, the voltage readings will be lower because of the heat transfer. Here's the table :

    68 degrees F = 3.02 v
    86 degrees F = 2.62 v
    104 degrees F = 2.16 v
    122 degrees F = 1.72 v
    140 degrees F = 1.35 v
    158 degrees F = 1.04 v
    176 degrees F = .80 v
    194 degrees F = .61

    Ohms measures at the computer with the computer disconnected, or at the sensor with the sensor disconnected.
    50 degrees F = 58.75 K ohms
    68 degrees F = 37.30 K ohms
    86 degrees F = 27.27 K ohms
    104 degrees F = 16.15 K ohms
    122 degrees F = 10.97 K ohms
    140 degrees F = 7.60 K ohms
    158 degrees F = 5.37 K ohms
    176 degrees F = 3.84 K ohms
    194 degrees F = 2.80 K ohms

    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, 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

    Vacuum diagram 89-93 Mustangs
    http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
     
    #7
    Last edited: Nov 14, 2013
  8. Nathan Keen

    Nathan Keen New Member

    Joined:
    Jul 9, 2013
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    2
    OK, i finally got the car to idle without the clutch pushed in. All I had to do was plug in the clutch safety switch on the transmission. I have checked and troubleshooted (shot?) all codes in the previous post and all are getting power and are in range. I changed the BARO sensor as the stock had a huge crack in the bottom.

    Now it is throwing some of the same and more codes:

    22
    31
    67
    51
    53
    54
    66
    96

    The car idles fine, a little lopey, but will do it as long as there is fuel in the tank.

    When I put the car in gear, the idle rises slightly (200-300 more RPM). When I rev and let the clutch out, the car dies (not a can't-drive-a-clutch stall). The new codes are worrying. Any thoughts would be appreciated.
     
    #8
  9. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,822
    Likes Received:
    403
    Trophy Points:
    134
    Location:
    Dublin GA
    Clear the codes from memory, run for a while and dump them again. The easy way to clear codes is while the codes are dumping, disconnect the jumper used to dump the codes or disconnect the code reader.
     
    #9
  10. Nathan Keen

    Nathan Keen New Member

    Joined:
    Jul 9, 2013
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    2
    OK, I have the engine running smooth and most of the codes gone. I still am having issues with it dying when putting in gear and attempting to drive. There are two codes left: 67 and 85. It is my understanding that 67 can be either a memory code (A/C related) or clutch switch issues. Code 85 is the same, but it pertains to the sensor in the transmission. How would I go about testing to determine which is bad? (BTW, my A/C is not hooked up).

    Also, My car was not equipped with a VSS. I have read that on Mass Air cars, this is important. It has the wires loose under the car (Orange and Green). I purchased the plug with the pigtails. The problem is, the wires on the plug are both white! Again, any help in how to determine which is which would be great!

    Thanks for all the help, you have saved me a lot of money!:nice:
     
    #10
  11. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,822
    Likes Received:
    403
    Trophy Points:
    134
    Location:
    Dublin GA
    The VSS sensor is one of the few sensors that doesn't care which color wire it is connected to. Just be sure to solder the pigtail wires and cover the solder joints with heat shrink tubing for a water tight connection.

    Code 85 - CANP solenoid - The Carbon Canister solenoid is inoperative or missing. Check vacuum lines for leaks and cracks. Check electrical wiring for loose connections, damaged wiring and insulation. Check solenoid valve operation by grounding the gray/yellow wire to the solenoid and blowing through it.
    The computer provides the ground for the solenoid. The red wire to the solenoid is always energized any time the ignition switch is in the run position.

    Charcoal canister plumbing - one 3/8" tube from the bottom of the upper manifold to the rubber hose. Rubber hose connects to one side of the canister solenoid valve. Other side of the solenoid valve connects to one side of the canister. The other side of the canister connects to a rubber hose that connects to a line that goes all the way back to the gas tank. There is an electrical connector coming from the passenger side injector harness near #1 injector that plugs into the canister solenoid valve. It's purpose is to vent the gas tank. The solenoid valve opens at cruse to provide some extra fuel. The canister is normally mounted on the passenger side frame rail near the smog pump pulley.

    [​IMG]

    It does not weigh but a pound or so and helps richen up the cruse mixture. It draws no HP & keeps the car from smelling like gasoline in a closed garage. So with all these good things and no bad ones, why not hook it up & use it?


    The purge valve solenoid connector is a dangling wire that is near the ECT sensor and oil filler on the passenger side rocker cover. The actual solenoid valve is down next to the carbon canister. There is about 12"-16" of wire that runs parallel to the canister vent hose that comes off the bottom side of the upper intake manifold. That hose connects one port of the solenoid valve; the other port connects to the carbon canister.

    The purge valve solenoid should be available at your local auto parts store.

    Purge valve solenoid:
    [​IMG]


    The carbon canister is normally mounted on the passenger side frame rail near the smog pump pulley.
    Carbon Canister:
    [​IMG]
     
    #11
  12. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

    Joined:
    Feb 19, 2001
    Messages:
    21,703
    Likes Received:
    320
    Trophy Points:
    124
    Location:
    Massachusetts
    Your car should have a VSS. In the later years it was critical to mass air. The only 5.0's that didn't come with a VSS are the 86-88 Speed density mustangs without cruise control. If you convert those to mas air, you need the VSS
     
    #12
  13. Nathan Keen

    Nathan Keen New Member

    Joined:
    Jul 9, 2013
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    2
    Alright, I have the above problems fixed. Now the car idles fine, but now has a weird issue. When I rev the car up it will hold the rev. for several seconds before stuttering and sputtering, but not dying, only dropping to between 200 and 500 rpm. Once I let off the throttle and give it a little blip of gas, it goes back to idling smooth as silk. Any thoughts?
     
    #13
  14. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,822
    Likes Received:
    403
    Trophy Points:
    134
    Location:
    Dublin GA
    Just for clarity's sake, are all the codes gone? If not which ones remain?
     
    #14
  15. Nathan Keen

    Nathan Keen New Member

    Joined:
    Jul 9, 2013
    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    2
    No, there are still plenty of codes.

    I got it running good enough to go take it out for a spin for the first time in 10 years. ran good for a while, but then it started to act silly. Here is a list of new codes that I've pulled after the drive:

    12
    22
    29
    31
    51
    53
    54
    66
    96

    I got to looking at all the grounds were corroded like crazy. I went through and clean them all and put a new main negative to block cable on.

    I put a new map sensor in about a month ago.

    The speedo died halfway through the DrIve so I need to take out the speed sensor and inspect it.

    I replaced both coolant sensors.

    the throttle position sensor is receiving voltage within the range specified. at least that was before I drove it.

    Damn it was fun to drive, but it is a piece of work! any help is appreciated...

    BTW, jrichker, thank you so much! without you this day would not have been possible. once its running real good, there will be a ceremonial burn out In your name.
     
    #15
  16. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

    Joined:
    Mar 10, 2000
    Messages:
    21,822
    Likes Received:
    403
    Trophy Points:
    134
    Location:
    Dublin GA
    Clear the codes by disconnecting the test jumper while the codes are dumping, or press the clear codes button on your scanner. Drive it a day or two and dump the codes again. Post what you get and I'll do my best to help you.
     
    #16

Share This Page