einzelherz

Car is a 4 door manual transmission with around 180K on the odometer. I have a handful of strange throttle problems that in my head, could all have a single problem causing them.

1. On a hot day with the a/c on (it itself is another host of problems) if I have been idling in a parking lot for a while the engine will speed up to between 1500-2500 rpm out of gear and off throttle. If I have it in gear during this time, the car will accelerate just as an automatic would. Turning the AC off doesn't fix the problem it just changes the too-high RPM range.

2. The car has never had a stable idle. This is mostly apparent in stop and go traffic when at one light I'll be at 900rpm and the next I'll be at 550 trying to stall. This is usually without the AC on and on a normal temperature day.

3. There is a distinct stutter almost exactly at 2500rpm regardless of engine temperature. It's only noticeable in lower gears when the torque is being multiplied and at partial throttle. It almost feels like a misfire. This is a newer problem.

4. When cold, above 3000rpm the engine stutters and lurches like crazy. It was much much worse (engine would basically cut out) before I re-ringed the pistons (2 had low compression, 2 were burning a ton of oil). Once the car is at operating temperature, this completely vanishes. This problem started a few months before the rebuild around the time when I was burning 1qt/400 miles.

The car had been very poorly maintained when I bought it (which makes me an idiot). I had to replace the coil and ignitor last novemberish. Everything is stock and the last time I checked (a month after the rebuild) the compression range was within 10 points of each cylinder. I cleaned out the IACV last year trying to solve the inconsistent idle.

I'm hoping this is all possibly being caused by a faulty throttle sensor or something, but based on the cars history thus far, it probably won't be that simple.

Thanks in advance.

einzelherz

Monday morning bump.