Sorry if this is the wrong forum, but I wasn't sure where to post it. My 93 Roadmaster Wagon has started idling weird. If I'm stopped the idle will start fluctuating between 1000 RPM and 600 RPM. There were a couple times it was more extreme, but it hasn't done that for a while. Any ideas where to start? Here's some more history: The check engine light came on a month ago, said the O2 sensor was lazy (or slow, I forget the exact message but I replaced it and the light hasn't come back on). When the car is cold I have to crank it longer than normal to get it started. I believe the TCC solenoid is going out, I can feel it jerk as I come to a stop. I plan on replacing it soon. Don't know if these have any bearing on the problem, but thought I'd mention them just in case. TIA, baking Maybe it just doesn't like standing still... :laugh:
Sounds like it may need an idle relearn, or the Idle Air Control Valve is not working correctly. You may also want to check functionality of EGR valve. A few things can cause this.... from minor tune up items to crank sensor. One item that is common in alot of cars for causing this is when the fuel pressure regulator starts leaking, allowing the engine to suck fuel right into the vacuum lines. When you shut the car off, the excess pressure then bleeds off through the regulator and into the engine, where it basically creates a "flooded" situation upon restart. This can also be part of the cause for the surging because of uneven fuel pressure, or just not enough pressure because of the leak. Hope that helps alittle.... Mike
Sometimes a fluctuating idle means a bad throttle position sensor. Best thing to do is find someone with a scanner and check all the sensor values, and stored codes. If the check engine light went on, the computer more than likely stored 1 or more codes. Good Luck.
Check engine light hasn't come on since I put on the new O2 sensor. I had the battery disconnected when I installed it, so hopefully the codes were cleared. I'll have access to a code reader Monday, I will check then to see if there are any stored codes. Thanks!!
Battery disconnected........... did it start doing the surging shortly after you did that? Bet you just need a idle relearn. I am at home and don't have my shop key software here........anyone else have a idle relearn procedure handy for Brian? Mike
Success!!! You guys rock!!! Finally got a chance to work on this. I replaced the IAC valve, car idles smoothly and starts as soon as I hit the key. Car has 130,000 miles and now it starts and runs like new. Thanks for the help!!!!!!! baking :beer
