So you believe it is an electrical issue and not a fuel issue?
The IAC(idle air control) valve is how the computer controls the idle.
700rpms warmed up.
The IAC uses a step motor connected to a valve on an air passage inside the intake.
It is, in essence, a controlled vacuum leak.
Step motor allows computer to return/set the valve at the same place each time.
Most engines will die if IAC valve is unplugged while engine is idling, they should drop to 500rpms, lol, but most die.
If IAC Valve was "dead" then most engines would not idle.
It can be removed and tested, just connect it while it is off and turn on the key, you should see/hear the motor and value move.
Does it backfire when engine is cold?
If so then either spark is too advanced or valve timing is wrong.
If it only back fires when warmed up then fuel mix is too lean, hot cylinder is igniting it before spark plug can.
Does it have "power" if you drive it at higher RPMs?
If it lacks power it could be valve timing, lack of fuel or MAP sensor, I assume you have checked the MAP sensor's connector and vacuum line and they are both OK, MAP sensors rarely fail, not never but rarely.
If you unhook a MAP sensor on a running engine it should still run but will develop a lope at idle and have poor acceleration, but would still be drivable.
Any compression numbers?
You would expect 150+ psi on all 4 cylinders
Lower on all 4 would be valve timing issue.
Does the CEL(check engine light) work?
Does it come on with the key and then go off?
If not it may be disconnected or you have a computer problem.
I would try to read the codes
Last edited by RonD; 05-04-2014 at 02:13 PM.