s13 91 240sx Idle Problem

I have been enduring a very rough ilde when I disengage the clutch, sometimes stalling out completely! I’ve search around for a solution and have come up with a lot of unanswered suggestions. The most promising results come from the Nico Club forums.

Hello,
Sorry for first post. And sorry for another idle issue question for the 240sx

I am having trouble with high idle after the car has already warmed up. 1993 240sx ka24de, with removed Pair valve and pairc solenoid stuff (per p00t’s post)

I have followed the FSM for diagnosis of the “High Idle After Warm-up”. First step was to test the iacv-aac. I just removed the bugger like so many other posts suggested. Cleaned with B-12. tested AAC solenoid with battery, heard it click/ cleaned it a little. Tested the IACV, 10.2 ohms. Cleaned it, and checked plunger.

Put it all back together, and got it running. Does the same thing. Idles about ~1500 (maybe less) until warm. Idle goes down to about 1000~1100 and my car seems like it stutters ever so slightly. On a rare occasion, out of the blue it will stutter and go down to about 400~500 rpms and almost die and then catch itself and idle back up.

Driving is a different story. During shifts (5speed) or when in neutral coming to a stop, idle will go completely limp like it’s trying to idle correctly (1000), but then it compensates and the idle will be high 1500~1700 and stay there for about 15-25 seconds. Then go back down to 1000.

Next was check air intake leak… Didn’t check it all THAT good. Just sprayed some B12 around everything, and the idle didn’t change or anything.

Next step was to remove O2 sensor and race engine @2000 no load for about 30 seconds. So I unplugged O2 sensor, started car, revved it up to 2000, it sat there fine for about 15 seconds, then the car started missing bad, started to stall, let of the gas, car idled real funny so I killed it.

What to check next???????????????????????
02 sensor bad? MAF ground bad? Hidden Vacuum leak??? POS car???

Sorry for the longest post ever in the history of forums. But you guys are about the only ones on the internet with any idea of how to fix these cars.

Read the whole thread on cleaning your IACV to fix the idle problem.