3800 completed but is idling at almost 1700 rpm. i have checked all the vacuum lines and fluids i have no air leaks and the throttle body is working just fine. cant this me a computer problem???
Sure it could. You should start by removing the IAC and then inserting your finger to fully seal off the passage that has vacuum on it. Does the engine stall, or run well below idle speed? If so then you know the problem is the IAC pintle too retracted. The next question will be is the problem caused by the IAC, the PCM to IAC wiring, or directed by the PCM itself.
If sealing the IAC with your finger however does not slow down your idle speed, then you need to look for either a vacuum leak or a non-fully closed throttle
i took off the IACand placed my thumb over it and still had a high idle i also replaced the IAC and its still running at 1700 rpm. then i put vac plugs on all the vacuum lines and ports and still no change... i am completely stumped at this point
For the engine to run at 1700 rpm, somehow air is getting into the intake manifold. Vacuum lines disconnected are not going to get you to that speed, with perhaps the exception of the large vacuum brake booster line.
You covered the IAC hole and the engine still ran fast. That eliminates the IAC, the IAC wiring, the PCM and any electronic sensors.
Is your throttle closing completely?
Did you eliminate the EGR valve and not fully seal the hole in the lower intake manifold?
i took off the IACand placed my thumb over it and still had a high idle i also replaced the IAC and its still running at 1700 rpm. then i put vac plugs on all the vacuum lines and ports and still no change... i am completely stumped at this point
I doubt your thumb could have fit way down in the hole. to block the IAC passage you have to jam something all the way down the hole and seal it off completely.
I have a very similar problem , I have put a new IAC on no change I also checked for manifold leaks and throttle body leaks. Also throttle cable Still no change. Did you ever find your problem?
I would say double check the IAC again and make sure you are plugging it off completely as well as make sure the throttle is not being kept open some by the cable set up. If not check for vac leaks around the throttle body to manifold gasket and you did plug the larger vac port for the brake booster as I had one a few years ago with a small hole in the metal brake booster tube going through the car that was very hard to track down. Dan
I have a very similar problem , I have put a new IAC on no change I also checked for manifold leaks and throttle body leaks. Also throttle cable Still no change. Did you ever find your problem?