I've been dealing with an idle problem for the past three months or so and its driving me nuts. I'll do the best I can to describe it. I'd describe what happens as almost a slight miss. For a split second the RPM drops and during this drop I notice the volt gauge and oil pressure gauges also fluctuate. The display on the instrument panel also flickers a bit. The problem seems to be intermittant. After this "miss" it will often idle completely normal for awhile. It seems to only occur at idle with the car in drive and my foot on the brake, although sometimes I think I feel it a bit in park as well. I don't feel it while driving, but some have suggested its still there, but is just more difficult to notice. It also seems to happen only once the car has warmed up. The only code I've seen is a 32, but I've routinely gotten that code, even before the problem started.

I think I've replaced all the usual "bad idle" culprits. The problem started not long after I replaced an alternator, so my first thought was that. I installed a second alternator (under warranty) with no change. Spark plugs were replaced and cap/coil are fairly new (Hypertech) and appear in good shape. I replaced the ignition module, as well as the ignition pickup with no change. I replaced the IAC motor and thoroughly cleaned the throttle body and IAC passages. The EGR valve and solenoid were also changed along with the vacuum line that runs in between them. I also replaced the fuel filter and O2 sensor. I haven't replaced the TPS sensor, but it did test ok. I'm starting to run out of ideas. Now I'm starting to wonder if there could be a problem with the ECM itself or maybe some type of fuel problem? Has anybody experienced a similar problem that might have some insight. Thanks, Tom


[Modified by TA, 2:50 PM 6/3/2003]

 

Tom - Did you replace the spark plug wires ?

Also, pop your hood at night and look for arcing wires. Check by the distributer and also near all the spark plugs. I once had 2 bad wires on my Iroc and it was like a fireworks show when I poped my hood in the dark.

Vic




[Modified by Vic'89, 3:35 PM 6/3/2003]

 

Hey Vic, the wires are pretty new and I've looked them over and they appear to be ok, but I'll double check tonight for arcing.

 

Wow man, you shoulda called me over, fireworks are fun to watch. :D

 

I just checked it while in the garage, with the lights out...........pitch black

 

Sounds as if you have a loose connection with the power. You are loosing power to everything. Have you installed a volt meter to the alternator directly? Then try to the battery directly. I would also check the ground cable. This could be loose. Have you tried this with the headlights on? I am wondering if the headlights get dim, This would point me in the direction to look a short or loose connection.

 

The alternator and the battery seem to test out fine, but I'll double check all the connections to be sure.

 

TA - the symptoms you have described are exactly what I encountered after I changed the cap/rotor/plugs/wires. It took me awhile to find the problem because it was an intermittant miss occuring only after the car had warmed up pretty good. It turned out to be a plug wire arcing up from the boot to the underside of the dipstick housing, but I had to be at just the right angle looking at that 1 plug wire when the miss occured to notice it. Don't know if this is your problem or not, but hope it turns out to be something as simple as mine. Good luck