1994 Grand Am Rough Idle/not Starting

replaced the iac valve and still have service engine soon light. checked the code told me iac that's not it! Had tune up done now car isn't starting after it's been sitting over night. while i drive if i let off the gas it stumbles every time. has a new starter alt. good. battery is good. don't know if it's a fuel system problem or a catalytic converter or something else HELP PLEASE

did you clear your codes after installing the new part? If you didn't, the computer is still bypassing the iac and will not correct itself until after 50 start/ stop cycles. Disconnect your battery for a few minutes and then take the car for a drive. the computer will recalibrate itself, and should cure the problem. IF the iac code comes back, then you may have gotten a bad one, which could happen

Also, I've heard that the passageways leading to and from the IAC can become plugged with carbon deposits and such. If you still have problems like those before you replaced it, and you've reset your computer, be sure that the passageways are clear.

stil have the problem with the iac valve. disconnected the battery and the engine light went out for about a day and a half but now it's back on. i had a mechanic say that it could be the air intake gasket but i don't want to replace stuff i don't need to any ideas? is the mechanic just bs me or what

is there another way to get the codes off my computer? i have a code scanner but it's for a obd1. is there a cheap way to get the codes? :banghead:

anyone with an obdII car (96-newer) can go to Auto Zone or Advance and get your codes read for free. your 94 car should still be obdI, so you should be able to check it yourself. Some 95 cars have a hybrid system which takes a special adaptor to check.