Engine starts then runs for a period of time until it warms up, then fans come on and then EGR clicks on and off every other second , then it eventually quits. Replaced the coolant temp sensor. And it never sets a code. Have checked wiring for shorts and nothing. Is it a ECM going bad?? When trying to drive it , it will only go about a half a block , then quits , Then will start up again.???
Year, make, model, miles, etc?
1990 Pontiac Grand Prix with 121000 miles. Scan shows all items within limits or normal.
I don’t know who is scanning or with what, but maybe something better is in order. Or maybe better yet, just plain old horse sense without having to ask the computer.
If you’re saying that the EGR is active at idle then there is absolutely something wrong there since the EGR should do nothing at idle. If it opens at idle the car will run terribly and can easily be stalled.
One common problem for GMs with this kind of issue is a bad crankshaft position sensor. So that is also worth a look.
Either of these things can cause problems without throwing codes.