Lately, I've been having trouble with the wife's 96 Mystique w/zetec/atx.
First, when I go out for a cold start, the engine will idle at about 1500rpm on startup then work its way down to about 800 in about 1 minute. If I just nudge the gas pedal or turn on the headlights during this time, the engine goes to about 200rpm for about 3 seconds and then dies. Even when the engine is warmed up, if I tap the gas, it almost seems to want to stall out.
Secondly, the engine idles real smoothly at just a tad under 800 rpm when in park. Putting it in any gear causes it to drop to about 500 rpm. I don't think this is a real problem. But sometimes the steering wheel vibrates so badly, it feels like I'm holding a gas-powered weed-eater. If I put my foot on the brake and give the engine a little gas, the vibration goes away.
Now that you have my main compaints, hopefully someone can help me cure (or at least lessen) my problems. My main questions:
Can the IAC valve cause all these problems?
What is the typical idle for these engines?
Will changing to a computer from a newer model Contique help/hurt any (I can get them for about $10 apiece)?
I've replaced the timing belt, engine mounts, oil, filters, checked all vacuum lines. Vacuum is a steady 20". TPS has been changed. Computer was reset after every part was changed.
I'm thinking of doing the IAT mod, but I'd rather not do mods yet (like I said, it's my wife's car
). I've also just spent about $500 in parts to do the belts and related parts. So, I don't want to spent an awful lot more in this car.
