I got a 94 VW Jetta idle rpm problem. Sometimes when I start, the tachometer would go up to ard 1400 rpm. Once in a while, while driving at 2800 rpm, and when I go to neutral gear, or step on the clutch, the tachometer will stay at 1800 or 2200 rpm.
When stationary, the idle rpm should be ard 800 rpm, and when moving and no gears are engaged, it should be ard 1000~1100 rpm.
Okay, I have two questions before I'll start with this. First, why do you think your idle speed should be different when the car is stationary or moving? Second, I've been around cars all my life but have no idea what you mean when you say "ard xxxx rpm", please explain.
Depending on how long i switch off the engine, the idle rpm when i start
the car should be 800 rpm. When I switch off the car and go to sleep, and
start the car the next morning, the rpm will tend to be at 1000 before
going down to 800 rpm.
As for why the rpm is 800 when stationary, and at 1000 rpm, when the clutch is disengaged when moving, I am not really sure.
the internal computer of a car will increase the idle rpm of your engine untill it gets to a certain temp then it will go to a lower rpm so when you let it sit and the engine cools off at startup it will idle higher.