Hi guys.....well im new here....im in Alberta Canada ....heres my problem...i bought this car 7 years ago....ive replaced about 70% of the car...its had this idle problem since the day i got it....so far ive replaced the coil,dist. module,maf,set the timing did complete tune up plugs,cap rotor,wires...the 2 things i havent replaced is the o2 sensor & the IAC valve.....anyone ahve an idea which would cause it to drop to basicaly stalling like 400 rpm when stoping for a light or stop sign????? any help is appreciated.....

 

either of those or a vac leak.

 

I had the same problem recently. It turned out to be a dirty throttle body. Get a can of throttle body cleaner from your local parts store and clean the sh*t out of the TB. The air passages that allow the engine to idle when the throttle blade is closed can get clogged and cause a rough idle. My engine would often die at a stop until I cleaned the TB.

 

Yeah, that can work but it can also mess up your o2 sensor. I replaced the cpu and that changed everything for me. Car would backfire and stall but not anymore. I got mine from this forum.

 

^^^ Agree with the above. Either of those, or a vacuum leak. Additionally, you might want to disassemble the IAC motor (from the intake) and clean that out along with the IAC passages. There should be plenty of posts on how to do that if you use the "search" at the top.

The whole upper plenum can be taken out to have all that carbon cleaned out and it will probably make a world of difference. Dirty TPS can do this too, as well as a partially clogged cat. A long shot is TCC not disengaging. Look at the brake pedal. Above it there is a box with a largish vacuum line running to it, and next to it should be a box with 2 wires. That 2 wire box is the TCC lockup disengage switch. Unplug them and see if it changes anything. If so look more towards the tranny.

Make sure it's "throttle body cleaner" and not plain carb cleaner (which will strip a coating off the intake).