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I have been trying to get my 1982 Corvette running the way it's supposed to. I have replaced everything. I have had a couple professional mechanics work on it and still nobody can get it running properly. It finally starts fine and purrs like a kitten, but after a minute or two it just dies. When I drive it, it just isn't right. It will also die while driving, whether I'm going 35 mph or 65 mph. It even misfired on me today while attempting to drive it home. We have tuned and timed it and still this problems persists. When I come to a stop, especially when I place it in park, the idle shoots high, approximately 1200 rpms. Other times it goes up and down like a vacuum leak. We are convinced there are no vacuum leaks. All we can guess at is perhaps the ECM is bad. I did have Cardone rebuild one for me just last summer/fall. I've added a new chip from Summit Racing for a 1984 Corvette. Yes my Vette is a 1982, but I was told that is shouldn't hurt anything to have a 1984 ECM especially since the 1984 had the crossfire as well. I need help. Does anybody know the crossfire engine like the back of their hand? What can I do to get it running perfectly?
 

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When you were first describing your symptoms I thought maybe your fuel pump was dieing. But that wouldn't cause a misfire.
It has to be something electrical. I recently replaced the pick up coil on the distributor, but to no avail - same problem persists. ON another forum someone suggested that perhaps my ECM came from a car that had a manual transmission and if so it would cause the exact problems I am having. Do you have any input about that?
 

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I have been trying to get my 1982 Corvette running the way it's supposed to. I have replaced everything. I have had a couple professional mechanics work on it and still nobody can get it running properly. It finally starts fine and purrs like a kitten, but after a minute or two it just dies. When I drive it, it just isn't right. It will also die while driving, whether I'm going 35 mph or 65 mph. It even misfired on me today while attempting to drive it home. We have tuned and timed it and still this problems persists. When I come to a stop, especially when I place it in park, the idle shoots high, approximately 1200 rpms. Other times it goes up and down like a vacuum leak. We are convinced there are no vacuum leaks. All we can guess at is perhaps the ECM is bad. I did have Cardone rebuild one for me just last summer/fall. I've added a new chip from Summit Racing for a 1984 Corvette. Yes my Vette is a 1982, but I was told that is shouldn't hurt anything to have a 1984 ECM especially since the 1984 had the crossfire as well. I need help. Does anybody know the crossfire engine like the back of their hand? What can I do to get it running perfectly?
All of the '82 CrossFires used the same ECM's. The CrossFires have a frame mounted 25 micron fuel filter under the passenger seat that must be replaced every 25,000 miles because they WILL plug up and kill the engine. And their O2 sensors must be replaced every 25,000 to 30,000 miles because they also go bad. If your '82 has anywhere near 100,000 miles it needs a new fuel pump relay because after a while their points get carboned up and fail to energize the fuel pump. The relay is mounted to the rear face of the ECM so I recommend moving to a more accessible location like the top or right side of the battery. The ECM has ONE internal switch that controls the TWO Idle Air Control motors and when that switch begins to fail the IAC motors freeze in their present locations; meaning a real low or high idle. The idle speed is also controlled by the O2 sensor; high rpm when it's COLD and normal rpm when it's HOT. Before replacing any parts check the stored codes blinked by the CHECK ENGINE LIGHT.
 

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I have been trying to get my 1982 Corvette running the way it's supposed to. I have replaced everything. I have had a couple professional mechanics work on it and still nobody can get it running properly. It finally starts fine and purrs like a kitten, but after a minute or two it just dies. When I drive it, it just isn't right. It will also die while driving, whether I'm going 35 mph or 65 mph. It even misfired on me today while attempting to drive it home. We have tuned and timed it and still this problems persists. When I come to a stop, especially when I place it in park, the idle shoots high, approximately 1200 rpms. Other times it goes up and down like a vacuum leak. We are convinced there are no vacuum leaks. All we can guess at is perhaps the ECM is bad. I did have Cardone rebuild one for me just last summer/fall. I've added a new chip from Summit Racing for a 1984 Corvette. Yes my Vette is a 1982, but I was told that is shouldn't hurt anything to have a 1984 ECM especially since the 1984 had the crossfire as well. I need help. Does anybody know the crossfire engine like the back of their hand? What can I do to get it running perfectly?
Has the car been running like this for a while?
Did it just start?
Did you just get the car and are starting work on and found this.
some history would help.

I would connect a fuel pressure gauge to see if you have pressure when it dies.

A racing idle, has anybody messed with the synchronization of the throttle bodies?

the misfire, was it consistent for some time or just a few seconds?

how do you know it does not have a vacuum leak? Have you measured the vacuum?

when it dies does the tach drop to zero and dash warning lights come on after it dies or just before it dies?This could determine an electrical problem or fuel problem.

I‘m trying to find a simple pattern of the failure.
 

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Discussion Starter #6
All of the '82 CrossFires used the same ECM's. The CrossFires have a frame mounted 25 micron fuel filter under the passenger seat that must be replaced every 25,000 miles because they WILL plug up and kill the engine. And their O2 sensors must be replaced every 25,000 to 30,000 miles because they also go bad. If your '82 has anywhere near 100,000 miles it needs a new fuel pump relay because after a while their points get carboned up and fail to energize the fuel pump. The relay is mounted to the rear face of the ECM so I recommend moving to a more accessible location like the top or right side of the battery. The ECM has ONE internal switch that controls the TWO Idle Air Control motors and when that switch begins to fail the IAC motors freeze in their present locations; meaning a real low or high idle. The idle speed is also controlled by the O2 sensor; high rpm when it's COLD and normal rpm when it's HOT. Before replacing any parts check the stored codes blinked by the CHECK ENGINE LIGHT.
Thank you for the info. I have replaced the O2 sensor and the fuel filter. I have looked inside the compartment where the battery and ECM are located. Other than those two components with the wire harness I have seen nothing. Where is this fuel pump relay? I will look again in the morning. I have several friends who are professional techs and two of them have told me that, yes, while it sounds like an electrical issue it also sounds like a relay getting too hot and cutting out. What you say makes sense and I will check into it. Also, when I get my ECM back from Cardone who is going to check it over again for me just to make sure it is in good working order, should I replace the PROM chip with a 1982 PROM chip? I currently have a PROM chip for a 1984 Corvette since my ECM is from a 1984 GM vehicle. By chance do you know if most of the programming comes from the PROM or the ECM? I'm hoping ECM, which would then lead me to buy a new chip for a 1982 even though the ECM is from a 1984. Along with trying to locate and replace this fuel pump relay I am hopeful this will solve my issues. I have looked at Napa's inventory (I work there) and we have no fuel pump relays listed. I will search out of Corvette sites and see what they have. Thanks again. I'll let you know what happened as soon as I get my ECM back in a couple weeks from Cardone.

Steve
 
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