Engine Shuts Off - With and Without CEL

DualXhst289

Member
Aug 28, 2009
23
1
13
Picked up my 95 Cobra about 2 years ago, not starting. Pretty sure it had not been running in a few years before I bought it. Just got it running last week, but, it is dying with no CEL. What has been done: Long tube BBK, Prochamber H Pipe with no mufflers. Entire EGR system has been removed (yes I know doing so does nothing for performance) Have a EGR SIMULATOR chip installed in EGR plug. This is temporary as I will be getting it tuned, dont think it is doing anything anyway. Exhaust port is capped as well as vacuum lines.

What's happening: Idle is smooth, RPMs would hang when letting off of the throttle and when idling it would run for less then 5 minutes and shut down. It did not sputter, just shut down like it would when you turn the ignition off. No CEL. After this happened a few times, I kept it running by holding the throttle at about 2k. Then I got a CEL.

KOEO Codes: 122 TPS below min voltage....
552 Air Management Circuit 1 Failure
553 Air Management Circuit 1 Failure
558 EGR Valve Regulator Solenoid Circuit Failure
122
543 Fuel Pump Secondary Circuit Fault

I checked the voltage at the TPS and found it to be faulty. Replaced TPS. Erased Codes.

Engine continued to run smooth and die at idle, but, after about 10 minutes now. Throttle response was fixed. No CEL. Ran again at about 2k. 1 minute CEL. I shut it off and ran codes.

KOEO Codes:
552 Air Management Circuit 1 Failure
553 Air Management Circuit 1 Failure
558 EGR Valve Regulator Solenoid Circuit Failure
332 Insufficient EGR Flow Detected
543 Fuel Pump Secondary Circuit Fault
556 Fuel Pump Relay Primary Circuit Fault

Replaced fuel filter. Erase codes.

Engine continued to run smooth and die at idle after 2 minutes. No CEL. Ran codes.

KOEO Codes:
552 Air Management Circuit 1 Failure
553 Air Management Circuit 1 Failure
558 EGR Valve Regulator Solenoid Circuit Failure
543 Fuel Pump Secondary Circuit Fault

Erase Codes

Started again and ran at 2k RPM. CEL after 1 minute. Ran Codes.

KOEO Codes:
552 Air Management Circuit 1 Failure
553 Air Management Circuit 1 Failure
558 EGR Valve Regulator Solenoid Circuit Failure
332 Insufficient EGR Flow Detected

I know that 558 and 332 are obviously EGR related. 552 and 553, are these also EGR related or are they related to something else? IAC possibly? I didn't get 543 and 556 in the last 2 tests, but, it also didn't run for as long as it previously did. I'm doubting replacing the fuel filter fixed these codes. What is the next step to figuring out why it is dying?
 
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Chythar

15 Year Member
Aug 26, 2004
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552 and 553 are part of the missing emissions equipment. The 543 and 556 are the ones that are likely related to the problem - especially 556, which to me points to a CCRM issue. The fan, engine electrical and fuel pump relays are combined into the CCRM on our cars.

I had a similar issue I had with my old 1994 V6. It would randomly die while driving, but when the key was turned off the car would restart after a minute or two. Sometimes, it would restart immediately. I brought the car to a mechanic I trust, and he couldn't repro the issue. He had to drive the car for a week before he was able to repro it. The problem was the CCRM - the relay for engine electrical would kick off, basically killing power to the engine.

I'm not sure what to test in the CCRM after the issue happens. Hopefully someone else can chime in and tell you what wires on the CCRM to test for voltage, and see if it's the issue. Do you have access to another 94-95 Mustang? The part is the same for the GT and Cobra, so either will work. Swap the part and see if it helps.
 

DualXhst289

Member
Aug 28, 2009
23
1
13
552 and 553 are part of the missing emissions equipment. The 543 and 556 are the ones that are likely related to the problem - especially 556, which to me points to a CCRM issue. The fan, engine electrical and fuel pump relays are combined into the CCRM on our cars.

I had a similar issue I had with my old 1994 V6. It would randomly die while driving, but when the key was turned off the car would restart after a minute or two. Sometimes, it would restart immediately. I brought the car to a mechanic I trust, and he couldn't repro the issue. He had to drive the car for a week before he was able to repro it. The problem was the CCRM - the relay for engine electrical would kick off, basically killing power to the engine.

I'm not sure what to test in the CCRM after the issue happens. Hopefully someone else can chime in and tell you what wires on the CCRM to test for voltage, and see if it's the issue. Do you have access to another 94-95 Mustang? The part is the same for the GT and Cobra, so either will work. Swap the part and see if it helps.

I have not been getting 543 and 556 since replacing the fuel filter and adding fresh gas to the tank. I may be wrong, but, I believe that only the cooling fan, fuel pump and A/C system are controlled by the CCRM. I did a voltage test at the inertia switch and it is receiving 13.5 V though the stall. That should indicate the fuel relay in the CCRM is good.
 

DualXhst289

Member
Aug 28, 2009
23
1
13
Update: Car is still stalling after 15 minutes or so of idle. The RPMs are bouncing before the stall. Checklist of what I did today. Swapped dizzy with a spare a friend had, no change. This may be inconclusive though bc this dizzy is also 25 years old and may be bad. Was removed from his car last year in working order, but, who knows if it is still good. Put my old one back in. Tested voltage at the inertia switch on the wire that exits the switch. Had 13.5 volts through the stall. Pretty sure that eliminates the inertia switch and the CCRM as the problem. Tested voltage leading into the coil from the ICM. 13.5 volts through the stall. Should eliminate the ICM.

Trying to get my hands on a oscilloscope to test the PIP. I also read a article that it can be tested using a DIY LED test light. Also realized today that I have not replaced the cap and rotor, so will do that tomorrow.

When I get the PIP tested and if it passes, I am out of ideas......

As far as codes, I am now only gettting codes related to the EGR. I cant believe that changing the fuel filter and adding fresh gas got rid of the 2 fuel codes....
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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polk county florida
What is your fuel pressure engine running, vacuum line removed and plugged?
Same with engine running and fuel line attached?
 

DualXhst289

Member
Aug 28, 2009
23
1
13
What is your fuel pressure engine running, vacuum line removed and plugged?
Same with engine running and fuel line attached?
Are you refering to the vac line for the FPR? If so, I have not done a FP test with that vac line disconnected. FP is at 30psi at the schrader, with all lines connected normally.

I will check FP this evening with vac line disconnected and capped. Also going to clean IAC.
 

DualXhst289

Member
Aug 28, 2009
23
1
13
Smell the vacuum line to the fpr, if you smell gas the regulator is bad.
No odor from FPR. FP is 30 and 38. I didn notice that the fuel pressure is just below 20 during prime and FP drops almost immediately after turning engine off. Gets below 10psi with in 10 seconds. Shouldnt the fuel system hold pressure?

I may also be hearing a vac leak, but, I cant find it. Checked all vac lines and checked every mating surface with carb cleaner.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
17,928
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polk county florida
You stated the car sat for a time before you got it, I would install a new fuel pump, pressure is a little low. That will eliminate that problem then we can move on.
 
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