Bad ECM?
Pro
Joined: Oct 2009
Posts: 679
Likes: 0
From: vero beach florida
CLunk/bang is not very descriptive, is it coming from a certain spot or can you describe the noise better?
If it is running very rich, you could be getting gas buildup in a cylinder and it is hydro locking, meaning there is so much fluid in the cylinder that it is not letting the piston go up to the top of its arc.
Take out all spark plugs and turn the engine over, if there is no noise, you had fuel build up and you will have to change your oil, because the fuel leaked past the piston and into the oil.
Sounds like you have a bad ECM, do not buy one from autopartsgiant.com, took them 4 mths to refund my core.
Did you make sure the eprom was seated properly and none of the pins are bent or broken, I have seen that happen.
If it is running very rich, you could be getting gas buildup in a cylinder and it is hydro locking, meaning there is so much fluid in the cylinder that it is not letting the piston go up to the top of its arc.
Take out all spark plugs and turn the engine over, if there is no noise, you had fuel build up and you will have to change your oil, because the fuel leaked past the piston and into the oil.
Sounds like you have a bad ECM, do not buy one from autopartsgiant.com, took them 4 mths to refund my core.
Did you make sure the eprom was seated properly and none of the pins are bent or broken, I have seen that happen.
Thread Starter
Pro
Joined: Jan 2003
Posts: 567
Likes: 0
From: Oswego Illinois
The sound is like if you were to take a hammer and hit a piece of metal, no ringing just a loud short bang.
My ecm in the 92 should be fine I only swapped ecms to test the one that was in the 93.
It only started running rich after I put the ecm back in the 92 before it was fine.
Thanks ill have to remove the spark plugs and check for fuel build up and turn it over. When turning over should I just run the starter or turn by hand?
My ecm in the 92 should be fine I only swapped ecms to test the one that was in the 93.
It only started running rich after I put the ecm back in the 92 before it was fine.
Thanks ill have to remove the spark plugs and check for fuel build up and turn it over. When turning over should I just run the starter or turn by hand?
Last edited by vetteguy216; Apr 10, 2010 at 03:38 PM.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
The sound is like if you were to take a hammer and hit a piece of metal, no ringing just a loud short bang.
My ecm in the 92 should be fine I only swapped ecms to test the one that was in the 93.
It only started running rich after I put the ecm back in the 92 before it was fine.
Thanks ill have to remove the spark plugs and check for fuel build up and turn it over. When turning over should I just run the starter or turn by hand?
My ecm in the 92 should be fine I only swapped ecms to test the one that was in the 93.
It only started running rich after I put the ecm back in the 92 before it was fine.
Thanks ill have to remove the spark plugs and check for fuel build up and turn it over. When turning over should I just run the starter or turn by hand?
Thread Starter
Pro
Joined: Jan 2003
Posts: 567
Likes: 0
From: Oswego Illinois
Thanks for the help guys pulled spark plugs and there appears as though there was fuel in the cylinders, but now I need to figure out how/why it was in there.
1- Car is running fine
2- Swap ecms with one from a 93 so I can test it and make sure the ecm from the 93 is working properly.
3-go for a 10min test drive. ecm appears to be fine
4-but the original ecm back in.
5- Several hours later start up car to put it in the garage and it seems to be running rich. I park it and go to dinner.
6-Come home go to start car and wont start, there is now fuel in the cylinders.
Before I swapped the ecms to test the one from the 93 the car ran perfect now different story.
What could have caused there to be that much fuel in the cylinders?
1- Car is running fine
2- Swap ecms with one from a 93 so I can test it and make sure the ecm from the 93 is working properly.
3-go for a 10min test drive. ecm appears to be fine
4-but the original ecm back in.
5- Several hours later start up car to put it in the garage and it seems to be running rich. I park it and go to dinner.
6-Come home go to start car and wont start, there is now fuel in the cylinders.
Before I swapped the ecms to test the one from the 93 the car ran perfect now different story.
What could have caused there to be that much fuel in the cylinders?
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
The "bad" ECM might have left one injector grounded which would have let the fuel pressure bleed down into a cylinder. Just a thought.
Getting an ECM repaired with a hot problem is difficult, had one of these in my '95. I was able to find a re-man'ed from GM without a core charge, it still had to be flashed though. Suggest start shopping as a
93 ECM is going to be hard to find.
Getting an ECM repaired with a hot problem is difficult, had one of these in my '95. I was able to find a re-man'ed from GM without a core charge, it still had to be flashed though. Suggest start shopping as a
93 ECM is going to be hard to find.
