I purchased a 1998 Honda Civic automatic with 195,000 miles and I just purchased a 2000 used engine and when car is cold does not shut off but when it get hot it does. The revolution drops from 1100 to less than 500 and turns off. It does it with the AC on and off. The valve was cleaned and still shuts off. What can it be the problem?
What can it be the problem?
Many things when dealing with decades-old, high-mileage beaters. More detail is needed.
You said you purchased a used engine from a 2000 model but did not state if you have actually installed it yet. If so the 2000 engine may not be fully compatible with the 1998 car's electronics. If that's the case you would need to bring over the entire electrical system from the 2000 donor car. (You can't easily mix and match major components like engines in computer controlled cars like you can with something like a 1960s-vintage Chevy.)
What is "the valve" that you cleaned? Have you run a full diagnostic scan for codes and data?
