I have a 2000 Accord with a 3.0 v6 that started idling rough a few months ago. I've replaced all the spark plugs and even tried swapping out each ignition coil one by one to see if it was a coil problem and that didn't help. About two weeks ago, less than one minute after starting the car, I was driving through a parking lot and the engine began sputtering really bad and then suddenly picked back up and ran fine. This happened the next day too. Since the same thing happened in my truck once and was caused by a bad fuel pump I went ahead and replaced the fuel pump. Didn't change the way the car runs at all, but I have noticed that it idles very well during warmer weather. It has been 90 or more every day for a couple months now. On cooler mornings is when the idle is at its worst.
No fuel filter on this model, but I did replace the mesh bag on the fuel pump. I've also tried sea foam engine cleaner and it didn't make a difference. Any thoughts as to what could be causing the rough idle? Thanks.

 

Is the check engine light turning on while driving? Stop by an autoparts store and have them scan for codes, or use a code reader if you own one. Post the actual code(s) on here before attempting to replace any more parts. They start with the letter P and have four numbers, like P1234.

 

No, and I should have mentioned that. I have a code reader and it says there are no codes.