Need Help, Car Wont Start, I've Gone Through Both Checklists

93silverlx50

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A lot to digest here. I've read over this about 5 times, each time I get a little more comfortable and learn a little bit more after googling. So I started with testing the MAF. I get 12 volts on pin A. Pin B tests good for ground. When I test the signal return, pin D, I got 7.65 volts then .05 volts then .06 volts, not .5 and .6. I'm wondering if that's my whole problem.
 
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93silverlx50

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A lot to digest here. I've read over this about 5 times, each time a get a little more comfortable and learn after googling. So I started with testing the MAF. I get 12 volts on pin A. Pin B tests good for ground. When I test the signal return, pin D, I got 7.65 volts then .05 volts then .06 volts, not .5 and .6. I'm wondering if that's my whole problem.

I also tried starting the car with the MAF unplugged. It started and actually would idle, although choppy and rough, without it plugged in. When I plug the MAF in while running, it bogs down and dies every time.
 

jrichker

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MAF signals from the C and D pins do not use ground as a reference when doing voltage checks. You measure the voltage across the pins, not pin to ground.
 

93silverlx50

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MAF signals from the C and D pins do not use ground as a reference when doing voltage checks. You measure the voltage across the pins, not pin to ground.

So with the car at idle, or trying to at least, I checked voltage between pins C and D. Used the paperclip into the plug method. 0 volts no matter if positive on pin C and negative on pin D or vise versa, 0 volts
 
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93silverlx50

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So i went out to test the MAF again to make sure the paperclips were in all of the way. I started the car first without the MAF plugged in and it ran awhile in limp mode which is far better than how it runs when it wants to start. I then went and pulled codes yet again after resetting the computer. I got the usual EGR codes and 66 and 96. 66 says TOT sensor input fault (KOEO) or low MAF signal but I'm pretty sure that's on KOER. I can't find anything about the TOT sensor fault or what that could be.

I started a new thread so someone doesn't have to sift through all my crap. Can I test the MAF signal with the car is off? I tested resistance between Pins C and D and I got 3.98 ohms set at 200K. I tried testing Pin D with the red lead then the black to the battery ground (perhaps not accurate but Im just trying to see if there are any volts) but I got 0 volts.

The car was nice and warmed up so it would stumble a bit but of course it wouldn't start for me to get KOER codes.
 

93silverlx50

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20170903_115508.jpg
20170903_115534.jpg
That tells me that the MAF sensor element isn't working

I got it started after it sat and cooled for about 2 hours. It will still only start when it's cool or barely warm, not when it's hot no matter what. Also, it'll only start cool when I mash the pedal to the floor. I still seem to have soaked plugs after cranking and 38 psi for fuel pressure so I'm not sure if that means it could be starving for air until I floor it causing the TB to open.

I ran the codes again after testing the MAF which was between .1 and .5 volts from idle 500 to 600ish RPMS.

KOER
98 EPC Driver Failure in Processor

I have no clue what this means

66 TOT Sensor signal input below self test minimum, or babe air flow circuit below minimum E40D

I tested the MAF while running, it ran .10 to .50 at idle, about 500 to 600 RPMs. Should a new MAF solve this issue and remove this code? (I don't think there is suppose to be that much fluctuation within such a small RPM increase or decrease. If nit, what else could cause this code?

98 Duplicate
66 Duplicate
34 insufficient EGR Flow
85 Canister Purge Solenoid Cicuit Failure
34 Duplicate
85 Duplicate

10

29 Insufficient Input from the Vehicle Speed Sensor / Insufficient Input from Programmable Speedomoter / Odometer Module

34 Duplicate
66 VAF Mass Air Flow Sensor Fault, Below Minimum Voltage

Again, is the source of this the MAF sensor?

96 Fuel Pump Secondary Cicuit Fault / High Speed Fuel Pump Relay Open

I'll replace this relay when I find where it's located

29 Duplicate
34 Duplicate
66 Duplicate


I'm concerned with these NEW codes:
98, 66, 29 and 96.

I also pulled the plugs and found that a couple look good, nearly new but most have a black powder coating. I also checked injectors again and they are getting signal. I then put plugs in and cranked and found even the plugs that have the buildup are getting fuel as they were all soaked. I also checked each plug and saw each one fire, some seemed a bit stronger than others but they all spark. I pulled the upper intake to check for leaks but I'm not sure I see anything that looks off. The front 4 intake runners are definitely dirtier as they have more buildup inside.
20170903_111648.jpg
 
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93silverlx50

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This gets better and better. I was tightening up the upper intake bolts and SNAP, I broke one. Ran to Lowe's and picked up and tap and die set. Began to re-thread the hold after drilling the old bolt piece out and SNAP, that broke inside to hole too! Went to drill out that piece and SNAP, the freaking drill bit broke off in the hole too!!!! F*$% MY LIFE!

I ordered a helicoil kit hoping the hole isn't too large to use this, if so I guess I'll have to pickup a new lower intake.
 

jrichker

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It takes a machine shop and a special carbide drill bit to remove broken easy out and taps, Both of them are too hard to be drilled with anything other than a carbide bit. The carbide drill bits are very hard but they are also very brittle; it doesn't take much sideways motion or crooked angle to snap one. The machine shop will use a Bridgeport vertical mill or a drill press with a jig to keep the part in perfect alignment to use the carbide bit.
 
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93silverlx50

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So while waiting for my new lower I take I decided to take the valve covers off and check my roller rockers, they seem to be loud. About half were very loose. Pushrods looked good and nothing was broken. This motor was built roughly 15 years ago so I figured they needed to be snugged up. I began hand cranking the motor and adjusting all of them. I got to cylinder 3 and no matter how much I cranked neither the intake or exhaust rocker would move. I watched the lifters and on cylinders 3,4, 7 and 8, none of the lifters or rockers would move at all no matter how much I cranked. Would this be unusual, unusual for 8 to go bad seemingly at the same time. What else could I be looking at?
 

93silverlx50

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UPDATE:

Here is an update just because I hate reading threads that I think will help me only to find out whoever started the thread never followed up providing repair info.

In this thread I just found my block has a crack along the lifter valley and there is no movement of rockers, pushrods or lifters in the back half, cylinders 3,4,7 and 8. I guess my description the car was running on half it's cylinders was right on the money. Anyways, I'm not sure of the cam snapped, the crank snapped or why those cylinders aren't working, I'm not a mechanic although I feel like I have learned a lot from peoe taking the time to diagnose my issues. A big thanks guys, especially jrichker!
 

jrichker

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UPDATE:

Here is an update just because I hate reading threads that I think will help me only to find out whoever started the thread never followed up providing repair info.

In this thread I just found my block has a crack along the lifter valley and there is no movement of rockers, pushrods or lifters in the back half, cylinders 3,4,7 and 8. I guess my description the car was running on half it's cylinders was right on the money. Anyways, I'm not sure of the cam snapped, the crank snapped or why those cylinders aren't working, I'm not a mechanic although I feel like I have learned a lot from peoe taking the time to diagnose my issues. A big thanks guys, especially jrichker!
Sadly that's one problem that can't be fixed by the Cranks Ok But No Start Checklist.

However, I am glad to be of service in the education department, that's one of the reasons that I am here.
 
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RCrosson

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I've gone through both the cranks no start checklist and the surging idle checklist with no luck. The car has the following mods: 306, S Trim, E 303 Cam, Trick Flow Heads, Cobra Upper and Lower intake, 24lb injectors, calibrated MAF, Vortech FMU and pump, MSD 6AL box, MSD Boost Timing Master and the retard knob is at .25. (I have zero clue on how they work or how to bypass them)

When it ran, the car always had trouble cranking. It would slow crank and then start at a low idle then rev up to normal idle after about 2 seconds. It then ran great. When it was warm it seemed to slow crank if I tried to start it. I was driving it one day and it all of a sudden stumbled, popped and lost power. If I gave it gas the RPMs would drop. As I slowed to a stop, it died. Wouldn't start after that.

While going through the checklists I also replaced parts along the way. I've replaced the dizzy (used Motorcraft), ECT, ignition switch, IAB, cleaned MAF, cleaned salt and pepper shakers, cleaned EGR (car has no emissions) replaced the ECU, replaced the starter, replaced the plenum gasket, Base timing is at 9.

The car will occasionally start when it's cold. The idle bounces all around and it usually stalls. It sound like it's in limp mode. Today it started twice, once it started it died. I started it again as it was not warm yet and it stumbled around a bit, long enough for me to check timing. It doesn't respond to giving it gas.
I'm pasting the checklist below with my test results where the asterisk is. I know this is long but I am about at the end of my rope.

Cranks OK, but No Start Checklist for Fuel Injected 5.0 Mustangs model years 1986-1995

A word about this checklist before you start: it is arranged in a specific order to put the most likely failure items first. That will save you time, energy and money. Start at the top of the list and work your way down. Jumping around will possibly cause you to miss just what you need to see to find and fix the problem. Don’t skip any steps because the next step depends on the last step working correctly.

Revised 16 Mar-2017 to add information on the ignition switch fuse link.

All text applies to all models unless stated otherwise.

Note: 94-95 specific changes are in red

1.) Remove push on connector (small red/blue wire) from starter solenoid and turn ignition switch to the Run position. Place car in neutral or Park and set the parking brake. Remove the coil wire from distributor & and hold it 3/8” away from the engine block. Jumper the screw to the big bolt on the starter solenoid that has the battery wire connected to it. You should get a nice fat blue spark.
Most of the items are electrical in nature, so a test light, or even better, a voltmeter, is helpful to be sure they have power to them.

* Nice fat blue spark and coil also bench tested within range.

No spark, possible failed items in order of their probability:
A.) MSD, Crane, or other ignition box if present - Bypass it and return to stock configuration if possible. Do this as a temporary measure to eliminate it as a possible problem source.
B.) PIP sensor in distributor. The PIP sensor supplies the timing pulse to trigger the TFI and injectors. A failing PIP sensor will sometimes let the engine start if the SPOUT is removed. See paragraph 5A – Using a noid light will tell if the PIP is working by flashing when the engine is cranking.
C.) TFI module: use a test light to check the TFI module. Place one lead of the test light on the red/green wire on the ignition coil connector and the other lead on the dark green/yellow wire on the ignition coil connector. If the TFI is working properly, the test light will flash when the engine is cranked using the ignition switch.
D.) Coil
E.) No EEC or computer power - EEC or computer relay failure
86-93 models only: EEC relay next to computer - look for 12 volts at the fuel injector red wires.
94-95 models only: EEC or PCM power relay in the constant control relay module. Look for 12 volts at the fuel injector red wires.
Both 86-93 and 94-95 models: No 12 volts with the ignition switch in the run position on the fuel injector red wires. The relay has failed or there is no power coming from the ignition switch. Make sure that there is 12 volts on the red/green wire on the coil before replacing the relay.
F.) No EEC or computer power - fuse or fuse link failure
86-93 models only: Fuse links in wiring harness - look for 12 volts at the fuel injector red wires. All the fuse links live in a bundle up near the starter solenoid. Look for a 20 gauge blue fuse link connected to 2 black/orange 14 gauge wires.
94-95 models only: 20 amp EEC fuse in the engine compartment fuse box. Look for 12 volts at the fuel injector red wires.
G.) Ignition switch - look for 12 volts at the ignition coil red/lt green wire. No 12 volts, blown fuse link or faulty ignition switch. Remove the plastic from around the ignition switch and look for 12 volts on the red/green wire on the ignition switch with it in the Run position. No 12 volts and the ignition switch is faulty. If 12 volts is present in the Run position at the ignition switch but not at the coil, then the fuse or fuse link is blown.
Note: fuses or fuse links blow for a reason. Don’t replace either a fuse or fuse link with one with a larger rating than stock. Doing so invites an electrical fire.
Ignition fuse links may be replaced with an inline fuse holder and 5 amp fuse for troubleshooting purposes.
94-95 models only: Check inside fuse panel for fuse #18 blown – 20 amp [fuse
H.) Missing or loose computer power ground. The computer has its own dedicated power ground that comes off the ground pigtail on the battery ground wire. Due to it's proximity to the battery, it may become corroded by acid fumes from the battery.
In 86-90 model cars, it is a black cylinder about 2 1/2" long by 1" diameter with a black/lt green wire.
In 91-95 model cars it is a black cylinder about 2 1/2" long by 1" diameter with a black/white wire.
You'll find it up next to the starter solenoid where the wire goes into the wiring harness
I.) Computer. Don’t replace the computer just because you don’t understand how it works. Computers seldom fail, it usually is a sensor or wiring problem that causes the problems.
J.) Bad or missing secondary power ground. It is located between the back of the intake manifold and the driver's side firewall. It supplies ground for the alternator, A/C compressor clutch and other electrical accessories such as the gauges.

* Ground is good.

K.) Engine fires briefly, but dies immediately when the key is released to the Run position. Crank the engine & when it fires off, pull the small push on connector (red/blue wire) off the starter relay (Looks like it is stuck on a screw). Hold the switch in the crank position: if it continues to run there is a problem with either the ignition switch or TFI module. Check for 12 volts at the red/green wire on the coil with the switch in the Run position. Good 12 volts, then replace the TFI.
See the Ignition switch wiring diagram for more information on the ignition wiring fuse link because it is the next thing to be tested. You will need a Multimeter or DVM and know how to use the Ohms function to check continuity between the red/green wire on the ignition coil and the red/green wire on the ignition switch. Make sure that the ignition switch is in the off position when you do the check. You should see less than 1 Ω (Ohm) between the red/green wire on the coil and the red/green wire on the ignition switch. More than 1 Ω means that the fuse link may have blown open and needs to be replaced. If you get 1 Ω or less means the fuse link is OK and the ignition switch is bad.

* Replaced the switch

Wiring Diagrams:

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring Mustang FAQ - Engine Information 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

Complete computer, actuator & sensor wiring diagram for 94-95 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/94-95_5.0_EEC_Wiring_Diagram.gif


AutoZone wiring diagrams: You can navigate to the diagrams yourself via Repair Info | AutoZone.com and select the car year, make, model and engine. That will enable you to bring up the wiring diagram for your particular car.

2.) Spark at coil wire, pull #1 plug wire off at the spark plug and check to see spark. No spark, possible failed items in order of their probability: [/b]
A.) Moisture inside distributor – remove cap, dry off & spray with WD40
B.) Distributor cap
C.) Rotor
D.) Spark Plug wires
E.) Coil weak or intermittent - you should see 3/8" fat blue spark with a good coil

*Good spark at plugs.

3.) Spark at spark plug, but no start.
Next, get a can of starting fluid (ether) from your local auto parts store: costs a $1.30 or so. Then pull the air duct off at the throttle body elbow, open the throttle, and spray the ether in it. Reconnect the air duct and try to start the car. Do not try to start the car without reconnecting the air duct.

* Attempted with both spout in and spout out. No start.

Two reasons:
1.) If it backfires, the chance for a serious fire is increased.
2.) On Mass Air cars, the computer needs to measure the MAF flow once the engine starts.
If it starts then, you have a fuel management issue. Continue the checklist with emphasis of fuel related items that follow. If it doesn’t, then it is a computer or timing issue: see Step 4.

Clue – listen for the fuel pump to prime when you first turn the ignition switch on. It should run for 2-4 seconds and shut off. To trick the fuel pump into running, find the EEC test connector and jump the connector in the Upper RH corner to ground. The EEC connector is near the wiper motor and LH hood hinge.

* Fuel pump primes in run, once when turning the key to run for about 4 to 5 seconds and then again a short time later if you leave the key in the run position.

attachment-php-attachmentid-68357-stc-1-d-1322348015-gif.577651.gif


If the relay & inertia switch are OK, you will have power to the pump. Check fuel pressure – remove the cap from the Schrader valve behind the alternator and depress the core. Fuel should squirt out, catch it in a rag. Beware of fire hazard when you do this. In a pinch, you can use a tire pressure gauge to measure the fuel pressure. It may not be completely accurate, but you will have some clue as to how much pressure you have. If you have any doubts about having sufficient fuel flow/pressure, rent a fuel pressure test gauge from the auto parts store. That will tell you for sure if you have adequate fuel pressure.

* Fuel pressure is at about 38 to 40 lbs. Also, after continuous cranking the plugs are soaked.


4.) No fuel pressure, possible failed items in order of their probability:
A.) Tripped inertia switch – Coupe & hatch cars hide it under the plastic trim covering the driver's side taillight. Use the voltmeter or test light to make sure you have power to both sides of the switch
B.) Fuel pump power relay – located under the driver’s seat in most stangs built before 92. On 92 and later model cars it is located below the Mass Air Flow meter. Look for 12 volts at the Pink/Black wire on the fuel pump relay.
C.) Clogged fuel filter
D.) Failed fuel pump
E.) 86-90 models only: Blown fuse link in wiring harness. Look for 12 volts at the Orange/Lt Blue wire on the fuel pump relay.
91-93 models only Blown fuse link in wiring harness. Look for 12 volts at the Pink/Black wire on the fuel pump relay.
The fuse links for all model years 86-93 live in the wiring harness near the starter solenoid.
94-95 models only: 20 amp fuel pump fuse in the engine compartment fuse box. Look for 12 volts at the Dark green/yellow wire on the constant control relay module.
F.) Engine seem to load up on fuel and may have black smoke at the tailpipe. Fuel pressure regulator failed. Remove the vacuum line from the regulator and inspect for fuel escaping while the pump is running. If fuel is coming out the vacuum port, the regulator has failed. Check the regulator vacuum line for fuel too. Disconnect it from the engine and blow air though it. If you find gas, the regulator has failed.

5.) Fuel pressure OK, the injectors are not firing.
A.) The PIP sensor in the distributor tells the computer when to fire the injectors. A failing PIP sensor will sometimes let the engine start if the SPOUT is removed.
A noid light available from any auto parts store, is one way to test the injector circuit to see if the injectors are firing. The noid light plugs into the fuel injector harness in place of any easily accessible injector. Plug it in and try to start the engine: it will flash if the injector is firing.

I like to use an old injector with compressed air applied to the injector where the fuel rail would normally connect. I hook the whole thing up, apply compressed air to the injector and stick it in a paper cup of soapy water. When the engine cranks with the ignition switch on, if the injector fires, it makes bubbles. Cheap if you have the stuff laying around, and works good too.
B.) Pull an injector wire connector off and look for 12 volts on the red wire when the ignition switch is on.
C.) No power, then look for problems with the 10 pin connecter (salt & pepper shakers at the rear of the upper manifold).

* Check several injectors with my noid light. Noid light flashes as it should during cranking

See the graphic for the 10 pin connector circuit layout.
temp_hash-3ef2497fff29a7a9daee955cf93e5805-jpg.577652.jpg

The injector power pin is the VPWR pin in the black 10 pin connector.


D.) No power and the 10 pin connections are good: look for broken wiring between the orange/black wire on the EEC relay and the red wire for the 10 pin connectors.
E.) TPS voltage exceeds 3.7 volts with the throttle closed. This will shut off the injectors, since the computer uses this strategy to clear a flooded engine. Use a DVM, a pair of safety pins, and probe the black/white and green wires to measure the TPS voltage.
On a 94-95 Mustang, probe the black/white and grey/white wires to measure the TPS voltage.
It should be .5-.1.0 volts with the key on, engine not running. Note that if the black/white wire (signal ground) has a bad connection, you will get some strange readings. Make a second measurement using the battery post as the ground to eliminate any ground problems. If the readings are different by more than 5%, you may have a high resistance condition in the black/white signal ground circuit.

6.) Spark & fuel pressure OK.
A.) Failed IAB or improperly set base idle (no airflow to start engine). Press the throttle ¼ way down and try to start the car. See the "Surging Idle Checklist for help with all your idle/stall problems.

* Replaced IAB, won't start. Won't start with pedal 1/4 way down either.

B.) Failed computer (not very likely)

* Computer was replaced.

C.) Engine ignition or cam timing off:

* Timing is at 9.

only likely if the engine has been worked on recently. If you removed the distributor, there is a good probability that you installed it 180 degrees out of time.

* Stabbed dizzy 3 times to ensure it was 180 out

D.) Firing order off: HO & 351 use a different firing order from the non HO engines.
HO & 351W 1-3-7-2-6-5-4-8
Non HO 1-5-4-2-6-3-7-8

* Verified timing order and check plug wires for burns.

E.) No start when hot - Press the throttle to the floor & try starting it, if you get this far. If it starts, replace the ECT.

* Replaced the ECT, no start.

F. ) Engine that has had the heads off or valves adjusted. Do a compression test to make sure the valves are not adjusted too tight. You should have a minimum of 90 PSI on a cold engine.

* No work on motor

KOEO
34
85
34
85

Car won't start for me to get running codes since it ran for about 3 minutes while I verified timing.
Someone out there, can I get a list like this one for a 96 Mustang GT 4.6L 8-Cyl with manual transmission? I have an intermittant no crank no start issue.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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Someone out there, can I get a list like this one for a 96 Mustang GT 4.6L 8-Cyl with manual transmission? I have an intermittant no crank no start issue.
i went back and looked at your posts on this question, I also went through some posts in the sn95 tech threads, I will work on getting you some help and moving your question to the place it needs to be