Hi,
My 92 DOHC SL2 Saturn pulses noticeably at low speeds (higher also, but less obvious). It's like someone is playing with the gas pedal. I've changed the spark plug wires and plugs: no improvement. A mechanic also suggested I spray water on the coil packs to see if they are shorting: no change in engine idle during this test. There are no engine codes. I'm wondering if there is some kind of speed sensor that might be out of whack but not badly enough to trip a code. The engine seems to idle and run smoothly when the car is not moving. The problem is worse when the engine is warm.
Any suggestions would be welcome.
Roger