Hot restart problem
Thread Starter
Melting Slicks
Joined: Apr 1999
Posts: 2,521
Likes: 4
From: Windham, NH
Hot restart problem
I am trying to track down a problem for a friend of mine. The car is a 61,000 mile 92 LT1 6 speed convertible. Car starts fine when cold. Run the car for 15-20 minutes and shut it off. 4 out of 5 times the car will just crank over and will not run. Let it sit for 5 to 15 minutes and it will start & run!
I have checked the fuel pressure and it is 37 to 45 lbs and holds steady when shut off.
There is spark from the coil.
There is NO black smoke when it restarts.
I also checked the resistance of the injectors hot & cold. They were 11.2 ohms cold and 12.6 hot. All were within .1 ohm of each other.
I DID find that the injectors were NOT getting a signal when the car wouldn't run.
There is also an intermittant flash of the "SYS" light and "Security" light when the car is running and it will sometimes have the "Service ASR" light come on.
Any ideas?
I have checked the fuel pressure and it is 37 to 45 lbs and holds steady when shut off.
There is spark from the coil.
There is NO black smoke when it restarts.
I also checked the resistance of the injectors hot & cold. They were 11.2 ohms cold and 12.6 hot. All were within .1 ohm of each other.
I DID find that the injectors were NOT getting a signal when the car wouldn't run.
There is also an intermittant flash of the "SYS" light and "Security" light when the car is running and it will sometimes have the "Service ASR" light come on.
Any ideas?
Last edited by Jim Martley2; May 12, 2006 at 06:44 AM.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
As simplistic as this sounds did you check to see if there was any codes. It might give you clue. It sounds like you have localized the problem already. Right off hand I can’t think of any fail safe action the ECM might take to shut the injectors off to protect the engine, perhaps some others might. But I have read many posts that pre 94 ECMs were a problem in it self. I would assume you lost injector drive to both banks.
Since you have spark, that might eliminate the timing pulses from the opti which sets up timing for spark and injector timing in the ECM. Not sure how the flash of the "SYS" light and "Security" light when the car is running would relate because they are driven by the CCM. Not sure about the ASR but (no books here) I think it might be driven by the ASR module. Just for fun check the system voltage for a while and see if it is steady at the 14 to 14.5 volts. It has sounds of corruption on the serial bus but that is a real stretch. It would sure be nice to have a spare ECM just for testing purposes. Good luck.
Since you have spark, that might eliminate the timing pulses from the opti which sets up timing for spark and injector timing in the ECM. Not sure how the flash of the "SYS" light and "Security" light when the car is running would relate because they are driven by the CCM. Not sure about the ASR but (no books here) I think it might be driven by the ASR module. Just for fun check the system voltage for a while and see if it is steady at the 14 to 14.5 volts. It has sounds of corruption on the serial bus but that is a real stretch. It would sure be nice to have a spare ECM just for testing purposes. Good luck.
Thread Starter
Melting Slicks
Joined: Apr 1999
Posts: 2,521
Likes: 4
From: Windham, NH
Originally Posted by pcolt94
As simplistic as this sounds did you check to see if there was any codes.
I have gotten some suggestions that possiably the VATS system may be the culprit but I am not sure. I may take a chance and have the owner get the correct coded "VATS ByPass Module" from Ecklers just to try something. It is only $26 + shipping.
Thanks for responding.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
OK - From what I have heard from the ones experienced working on VATS is that it will not let you start the car. But once it is running will not normally no shut it down. I beleive it will inhibbit the start relay and fuel pump relay. Never heard of it shutting down the injectors.
I beleive this to be correct, tell me if im off base.
I beleive this to be correct, tell me if im off base.
Thread Starter
Melting Slicks
Joined: Apr 1999
Posts: 2,521
Likes: 4
From: Windham, NH
VATS had something to do with activating the FEDS system. I don't have the manual in front of me but it stands for Fuel Enable D???? System. According to what I read last night, it shuts down the injectors when VATS is triggered in the CCM. I am wondering if it has a "time delay" for FEDS as VATS does. It seems to take about the same time span, 3 minutes or so, for the injector pulses to show up after it won't run upon startup as it does if you "accidentaly" set off the vats system by incorrectly installing a resistor into the wiring to elimanate the key pellet and contacts in the ignition switch as a cause.
Am I making any sence??
Am I making any sence??
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
Check the ICM on the coil and make sure it's coated with thermal transfer or heat-sink grease. If it gets too hot, it'll cause engine performance like you're experiencing.
Advanced
Joined: Feb 2004
Posts: 72
Likes: 0
From: Huntsville Alabama
Originally Posted by Jim Martley2
There is also an intermittant flash of the "SYS" light and "Security" light when the car is running and it will sometimes have the "Service ASR" light come on.
Any ideas?
