Car: '97 Sunfire GT, 2.4/5-speed, 89700 miles, stock, owned since new. New spark plugs (AC-Delco) at 75000.
Originally I thought I had a sensor problems, see
thread
But now I think that I have an ignition problem, my quick question is has anyone had bad (weak) coil packs on there car, or a problem with the coil to spark plug interface (that rubber/plastic piece.
My problem is stumbing in high gear at a lower RPM under heavy throttle (only when warm.) No codes have been thrown. It almost seems like an old car with bad spark plug
wires. I have no noticeable change in fuel economy, car runs just fine cold.
I was testing the sensors with an OBDII scanner, the TPS seemed responsive, the O2 was crossing back and forth properly, and the MAP sensor was consistant to changes in throttle. But the ignition timing (degrees advanced) would drop to 3-8 degrees under this load (while engine was stumbling.) When cold same acceleration in high gear/low RPM the ignition timing was at 13-17 degrees. Other then the acceleration it was in the 20s and 30's or 0.0 under deceleration (where the spark stops anyway) in both warm and cold.
This is all pointing me away from fuel and sensors and towards ignition.
Thoughts?
I had to replace the Coil pack housing (white castle looking thing) and the spark plug boots on mine to sure a problem like that, also make sure the knock sensor is working properly as this will retard and advance the timming also.
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Hit 200 NA it broke once, Hit 213 it broke again,
Hitting 300 NA is further away than I thought.
Try replacing the Spark Plug Boots. You can get all four in a pack from autozone w/ a lifetime warranty on the boots for about $20
bullet wrote:Try replacing the Spark Plug Boots. You can get all four in a pack from autozone w/ a lifetime warranty on the boots for about $20
Auto zone's computer will tell you that you need wires instead of boots.
Ask for part # YCC. They come in a little bag and hang from the shelf behinf the counter where the spark plug wires are
