'91 Super coupe will not start..

Mranalla07

Registered User
My brother recently purchased a '91 auto super coupe. car ran well for a few weeks. I am told the vehicle would not start occasionally. He recently replaced the DIS module, cam sensor, crank sensor, ignition coil with no luck. He also has another EEC that is currently installed. Car sounds like it wants to start and occasionally will pop on a couple cylinders but not start. plugs and wires are new, although I bet the plugs are fuel soaked. OB0 is not my specialty, I work on OBDII vehicles currently. I have a new balancer that is not installed, when i removed the original balancer nothing was damaged or loose. maintenance records shows the previous owner replaced crankshaft bolt only, which through my research is a no-no and should be done with the balancer. At this point i want to start completely from step one and go through all wiring and checks. I had a code reader and service manual. only codes I am currently getting with the newer EEC installed is 114, 116, 212. code 212 says no input tac to eec (spout). i found what i think is the spout and it is clean and installed. Currently I am running to have the DIS MODULE checked at auto parts store and grab some testing leads to check the spout wiring from DIS connector to EEC. Where can i start with this ? Brother is ready to junk it and buy another vehicle.
 

Mranalla07

Registered User
Just to confirm-he replaced all those parts before even reading codes?
As far as i know yes. He read on this forum those parts are causes of no starts and replaced them. through-out the process he did have a temp sensor fault and replaced that sensor for that fault. the DIS, cmp sensor & ckp sensor were replaced due to the no start.
 

351tt

Registered User
Double check " every " under hood connector to make sure they are fully connected .. and the wire harness for any rub/break points as well as all ground connectors .
But with that said, the quick basics are .. Check spark , pull a lead off a plug if you can get at one , or install a spare lead at the coil pack with a spare good spark plug grounded to the engine [ not near any electronics etc ] while you spin it over , it should have a pretty good spark .
If you have spark , reinstall lead etc. then check for fuel pressure at the rail test port [ something like 40psi ? ] .
At this point it " should " run .. If you have spark and fuel , and even more so if you have raw fuel smell out the tail pipe, try holding the gas pedal to the floor while turning the engine over to help dry it out just in case its been [ way over ] flooded from past issues , or temporarily pull the fuel pump relay while you turn it over , but still at wide open throttle to get as much air threw as soon as possible to dry it out .
If your fuel pressure is down , make sure your pump is coming on , on prime [ initial key on ] it shouldn't sound like a bee on crack .. if it sounds ok, a clean buzz , check your fuel filter .
Also as a precaution you could check the oil for raw fuel smell , if its really bad change it right away before it does damage.
 

David Neibert

SCCoA Admin
My brother recently purchased a '91 auto super coupe. car ran well for a few weeks. I am told the vehicle would not start occasionally. He recently replaced the DIS module, cam sensor, crank sensor, ignition coil with no luck. He also has another EEC that is currently installed. Car sounds like it wants to start and occasionally will pop on a couple cylinders but not start. plugs and wires are new, although I bet the plugs are fuel soaked. OB0 is not my specialty, I work on OBDII vehicles currently. I have a new balancer that is not installed, when i removed the original balancer nothing was damaged or loose. maintenance records shows the previous owner replaced crankshaft bolt only, which through my research is a no-no and should be done with the balancer. At this point i want to start completely from step one and go through all wiring and checks. I had a code reader and service manual. only codes I am currently getting with the newer EEC installed is 114, 116, 212. code 212 says no input tac to eec (spout). i found what i think is the spout and it is clean and installed. Currently I am running to have the DIS MODULE checked at auto parts store and grab some testing leads to check the spout wiring from DIS connector to EEC. Where can i start with this ? Brother is ready to junk it and buy another vehicle.

Good luck getting the car to even run on an aftermarket DIS module. Try finding a used one instead.
 

Mranalla07

Registered User
Outside of the in-depeth walk-thrus in the factory 'Engine/Emissions Diagnostics Shop Manual' that sometimes relies on a factory brakeout box... Seen this troubleshooting procedure?

I originally went through that troubleshoot and got half way with no results. I have NOT used the engine/emissions diag, maybe i should try that. Plan is to go through that troubleshoot again with the newer EEC installed. I have also labeled all wiring from EEC to coil,dis, ckp,cmp and plan to check each circuit for continuity, short to power, or ground.
 

Mranalla07

Registered User
Double check " every " under hood connector to make sure they are fully connected .. and the wire harness for any rub/break points as well as all ground connectors .
But with that said, the quick basics are .. Check spark , pull a lead off a plug if you can get at one , or install a spare lead at the coil pack with a spare good spark plug grounded to the engine [ not near any electronics etc ] while you spin it over , it should have a pretty good spark .
If you have spark , reinstall lead etc. then check for fuel pressure at the rail test port [ something like 40psi ? ] .
At this point it " should " run .. If you have spark and fuel , and even more so if you have raw fuel smell out the tail pipe, try holding the gas pedal to the floor while turning the engine over to help dry it out just in case its been [ way over ] flooded from past issues , or temporarily pull the fuel pump relay while you turn it over , but still at wide open throttle to get as much air threw as soon as possible to dry it out .
If your fuel pressure is down , make sure your pump is coming on , on prime [ initial key on ] it shouldn't sound like a bee on crack .. if it sounds ok, a clean buzz , check your fuel filter .
Also as a precaution you could check the oil for raw fuel smell , if its really bad change it right away before it does damage.
I think I need to go through it all. Working at a Chrysler/dodge dealer diagnostic is not foreign to me, I am just seeming nothing out of the ordinary which has me stumped.

When i looked at the car weeks ago it had pressure, injector pulse and spark. It currently has a newer EEC installed. I have 40 of fuel at rail key on and drops to 38. holds 35 psi for over 5 minutes so i doubt i have an injector leaking. Fuel is in oil and will need to be changed ASAP. Cranking fuel does not drop below 38 psi. Brother states another shop installed pump and he replaced filter and none had it running. plugs are new but i bet fouled out. wires new also. When i am testing i usually hold it to the floor ( dry flood mode) to kill injectors from washing out cylinders. I have spark at all 6 coil to wires. Have not verified spark at end of plug wires but wires and spark plugs are new. I have power to coil with key on and also with it cranking so it can not be ignition switch. I went through the wiring diagram and wrote down all ignition circuits from the EEC to coil, cmp, ckp, and dis. I plan to load test and ohm check all those circuits along with the 30 point no start pinpoint test. when i pulled cam sensor someone told me check the synchronize.r Balancer only goes to 10 degrees on the atdc side so i guessed roughly 26 degrees and it appeared dead on. Cam sensor is new but i swapped it with a part store one. DIS was tested at oreilly auto and they state it passes all tests. the CKP sensor is also new. i have adjusted the gap with a match box. The damper is original and the previous owner replaced bolt only i assume it broke. I have a new balancer not installed. Although when i removed the original balancer nothing was damaged, loose or bent so i left original on car. Where are the important engine grounds located??


** My next step is to remove plugs clean and verify gap. check all circuits between the EEC and cmp,ckp,dis, coil . check grounds.
 

Mranalla07

Registered User
Good luck getting the car to even run on an aftermarket DIS module. Try finding a used one instead.
the 30 step pinpoint test all look good for tests on the dis. I occasionally get the 212 code for spout grounded. That circuit is between EEC, spout connector and DIS. Think the DIS could cause that fault code?
 

Mranalla07

Registered User
I have verified fuel pressure like previously stated 38-40psi. Load tested power to the pass. side front 2 injectors (red wire). verified with led test light injectors are firing when cranking on those 2 cylinders only. I would think the rest would be okay. I had spark before and the coil and DIS are new but i will test for spark at the end of the wires and check plugs. A compression test while I have the plugs out.. anything else I am missing? With spark and fuel I would think it should do more then it is.
 

351tt

Registered User
Once you verify the DIS is ok, you have the right recipe .. fuel , air and spark and assuming compression ..... potential spark at plugs but not verified at plugs , so pulling plugs and testing with existing wires to a safe ground would be my next test [ pull fuel pump relay to not blast raw fuel out the plug holes ] .
Open air spark is easier to jump than in cylinder under pressure spark but if it looks strong it should fire under pressure.
There also could be out of sequence spark plugs firing .. cam sensor/crank sensor damaged ? ... as in firing at BDC instead of TDC so still firing but quickly drowning in too much cylinder fuel .
Quick Start is always a good test to see if there is any shred of life in an engine but with the supercharge/intercooler etc probably not a safe thing to do .
I would still be checking every connector under the hood that you can get to ... a barely closed circuit [ improperly seated connector ] under higher electrical load can pull to an open circuit very easily and either shut down that circuit or intermittently mess up the computer signals to fire the plugs etc ... not necessarily what is happening but possible.
 

Mranalla07

Registered User
Once you verify the DIS is ok, you have the right recipe .. fuel , air and spark and assuming compression ..... potential spark at plugs but not verified at plugs , so pulling plugs and testing with existing wires to a safe ground would be my next test [ pull fuel pump relay to not blast raw fuel out the plug holes ] .
Open air spark is easier to jump than in cylinder under pressure spark but if it looks strong it should fire under pressure.
There also could be out of sequence spark plugs firing .. cam sensor/crank sensor damaged ? ... as in firing at BDC instead of TDC so still firing but quickly drowning in too much cylinder fuel .
Quick Start is always a good test to see if there is any shred of life in an engine but with the supercharge/intercooler etc probably not a safe thing to do .
I would still be checking every connector under the hood that you can get to ... a barely closed circuit [ improperly seated connector ] under higher electrical load can pull to an open circuit very easily and either shut down that circuit or intermittently mess up the computer signals to fire the plugs etc ... not necessarily what is happening but possible.
I had the code 212 appear after cranking engine. Code description is for EEC LOSS OF IDM / SPOUT SHORTED TO GROUND. I load tested and checked short to power/ground on the SPOUT circuit from EEC to DIS. Ohm'd out the wiring to 1.3 ohms and the SPOUT connector alone was 0.2ohms. Again this circuit was also load tested. More info led me to check the IDM circuit, which also splices off to the tac and tac connector. load tested from DIS to EEC and checked for short to ground. all checked fine with circuit able to carry load. I posted a cranking video on FB and someone mention my tac was not moving while cranking. That is why i chased the IDM circuit due to the splice to the TAC. I could see if the original EEC throws that code but my research says code 212 will NOT cause a no start. Unless its leading to a faulty DIS? I get signal from dis to coil and coil gets power and cranking along with DIS.
 

351tt

Registered User
QUOTE:
""Load tested power to the pass. side front 2 injectors (red wire). verified with led test light injectors are firing when cranking on those 2 cylinders only.""

As far as I know the injectors always have power , they are grounded at the comp to activate them , did you see the test light go on and off while turning it over to verify a pulse ?... you could also plug in a spare injector and turn it over feeling for the clicking while you do it .
Main grounds are at the front of the upper rad cradle on both sides , multiple wires into a single junction/terminal , also one on top of the rad directly in front of and from the battery .
No sure on the SC but on the 5.0 cars there is one on the passenger side of the engine down near the K member .
There is another one in the kick panel where the ECU is , directly off the main engine harness, it grounds to the body right at that point .
 

Mranalla07

Registered User
QUOTE:
""Load tested power to the pass. side front 2 injectors (red wire). verified with led test light injectors are firing when cranking on those 2 cylinders only.""

As far as I know the injectors always have power , they are grounded at the comp to activate them , did you see the test light go on and off while turning it over to verify a pulse ?... you could also plug in a spare injector and turn it over feeling for the clicking while you do it .
Main grounds are at the front of the upper rad cradle on both sides , multiple wires into a single junction/terminal , also one on top of the rad directly in front of and from the battery .
No sure on the SC but on the 5.0 cars there is one on the passenger side of the engine down near the K member .
There is another one in the kick panel where the ECU is , directly off the main engine harness, it grounds to the body right at that point .
I load tested the power feed to injectors with a headlight bulb no issues. Injectors have power whenever key is on. When firing injectors[cranking] pcm sends ground to them. I have verified ground on and off while cranking and can see it with my test light. Also if I ground out the injector my fuel pressure gauge drops so I know it's dumping fuel.

My next step is compression test, clean plugs and verify spark at the spark plug wire with a tester. With spark and fuel I should get a pop or something.
 

Mranalla07

Registered User
QUOTE:
""Load tested power to the pass. side front 2 injectors (red wire). verified with led test light injectors are firing when cranking on those 2 cylinders only.""

As far as I know the injectors always have power , they are grounded at the comp to activate them , did you see the test light go on and off while turning it over to verify a pulse ?... you could also plug in a spare injector and turn it over feeling for the clicking while you do it .
Main grounds are at the front of the upper rad cradle on both sides , multiple wires into a single junction/terminal , also one on top of the rad directly in front of and from the battery .
No sure on the SC but on the 5.0 cars there is one on the passenger side of the engine down near the K member .
There is another one in the kick panel where the ECU is , directly off the main engine harness, it grounds to the body right at that point .
Ground near the ecm? I am not seeing that. Do you know which ground number that is and where it connects on the frame?
 

351tt

Registered User
QUOTE : ""Ground near the ecm? I am not seeing that. Do you know which ground number that is and where it connects on the frame?""

I don't know the ground number , only that it comes off the PCM/ECU harness and its below the ECU around where the carpet lays up the side of the foot well ... I think alot of the EEC4 modules across the ford lineup have a wire/s off the engine harness near the ECU connector that grounds directly to the chassis .
Sounds like you have a drowned engine , there is a point of fuel saturation [ like a dirt bike or sled engine would do ] where you will get no sign of life.. where its just too much for even a brand new plug to light , in that case the only solution is to shut off fuel supply completely and spin the engine till it catches .
 

Mranalla07

Registered User
QUOTE : ""Ground near the ecm? I am not seeing that. Do you know which ground number that is and where it connects on the frame?""

I don't know the ground number , only that it comes off the PCM/ECU harness and its below the ECU around where the carpet lays up the side of the foot well ... I think alot of the EEC4 modules across the ford lineup have a wire/s off the engine harness near the ECU connector that grounds directly to the chassis .
Sounds like you have a drowned engine , there is a point of fuel saturation [ like a dirt bike or sled engine would do ] where you will get no sign of life.. where its just too much for even a brand new plug to light , in that case the only solution is to shut off fuel supply completely and spin the engine till it catches .
I will be pulling plugs soon. Also a spark and compression test coming. I see a ground point with about 4 wires. It appears to be part of another harness not the engine harness. Right under the carpet corner near door opening
 

KMT

Registered User
I was always under the impression that the main ground for the ECU is the bolt in the center of the connector - if you can reach it, be sure it is tight/snug. Not sure you can leave it out as it should be captured, same as the IRCM, I think.

Swapping ECUs around to troubleshoot sometimes leads to being in a rush & not tightening it back down, but that can lead to yet more tail chasing ;)
 
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