idling really high
guinness39
09-23-2005, 07:40 AM
The car is idling at like 3000rpms but once you put it in gear in drops to like 1400. The engine had got wet recently so something must have happened with that. Any ideas?
corning_d3
09-27-2005, 09:45 PM
Is there a service engine soon light? Does it do it with the air conditioner on/off? Just guessing, i'd say the IAC (Idle Air Control) motor. Again, just guessing
guinness39
09-28-2005, 07:30 AM
Yes, it still idles high with the air conditioner on
thermal izod
09-28-2005, 08:54 PM
could be an alternator issue too...
Johnny Mark
10-06-2005, 07:34 AM
The car is idling at like 3000rpms but once you put it in gear in drops to like 1400. The engine had got wet recently so something must have happened with that. Any ideas?
Hello Guinness39, I have had a similar problem with my '95 Monte Carlo, 3.4l DOHC for the longest time. Last year I took it to a dealer who put in a new PCM (Computer). That didn't fix it. I've consulted my Haynes manual and tested several sensors with my digital muti-meter. Based on discussion forums, I decided to change out the $31. IAC Valve (some refer to it as IAC Motor), even though my bench test indicated that it was okay. It must've been, because that didn't help. Other's had indicated an Intake Manifold vacuum leak. I wanted it to be anything but that, because the way those GM engineers have shoehorned this transverse engine into that engine bay, one can hardly get their hands in edge-wise. Anyway, I discovered that was indeed the problem. You can easily check for Intake leaks by removing the Fuel Rail Cover plate, to expose the two-piece intake manifold(s), and spraying a mist of ether towards the mating surfaces. My engine started reving, as it was drawing in large amounts of air where it wasn't supposed to be. This was screwing up the PCM readings from the sensors, causing the PCM to decide that, due to the amount of air the engine was receiving, it needed more fuel. At the upper limit of the rev (3800 rpm), it would over compensate the other way, and the engine would stall, unless I fluctuated the accelerator. I didn't look forward to the job, but it wasn't as bad as I had feared. Still, it wasn't easy, but now, for the first time in years, it's running great! Good luck!
Hello Guinness39, I have had a similar problem with my '95 Monte Carlo, 3.4l DOHC for the longest time. Last year I took it to a dealer who put in a new PCM (Computer). That didn't fix it. I've consulted my Haynes manual and tested several sensors with my digital muti-meter. Based on discussion forums, I decided to change out the $31. IAC Valve (some refer to it as IAC Motor), even though my bench test indicated that it was okay. It must've been, because that didn't help. Other's had indicated an Intake Manifold vacuum leak. I wanted it to be anything but that, because the way those GM engineers have shoehorned this transverse engine into that engine bay, one can hardly get their hands in edge-wise. Anyway, I discovered that was indeed the problem. You can easily check for Intake leaks by removing the Fuel Rail Cover plate, to expose the two-piece intake manifold(s), and spraying a mist of ether towards the mating surfaces. My engine started reving, as it was drawing in large amounts of air where it wasn't supposed to be. This was screwing up the PCM readings from the sensors, causing the PCM to decide that, due to the amount of air the engine was receiving, it needed more fuel. At the upper limit of the rev (3800 rpm), it would over compensate the other way, and the engine would stall, unless I fluctuated the accelerator. I didn't look forward to the job, but it wasn't as bad as I had feared. Still, it wasn't easy, but now, for the first time in years, it's running great! Good luck!
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