Contour Enthusiasts Group Archives Forums General Troubleshooting Rough Idle-Help!

I changed the plug wires, plugs, cleaned the MAF, I the car still will not idle smoothly.
My next steps were to check the coil pack and check the pcv valve. I did notice that the last time that I put gas in the car, there was no hissing sound when I took the gas cap off (and I have a CEL light, which I suspect is a bad gas cap). Could a bad gas cap effect the idle? Other than that, the car runs great.

Hi, I am from Chicago area too, and you are welcome to drop some posts in the Chicago forum.

Sometimes mine idles rough, but then it goes away. Not sure if it is worth spending $$ to have it diagnosed with an engine analyzer.

Actualy, the ldle gets realy rough at times. And the thing is, the engine was running so smooth before this started. I also added some FI cleanen to see if that is the culprit.

I have a CEL from a bad gas cap also (no hiss when you open it) and my idle has been fine even tho this is my 7th CEL in the last five months (it goes on for anywhere from a few hours to a few days and then goes out for a couple of weeks).

The fuel injector cleaner is a good idea as long as you don't go overboard with it. If you notice any improvement you're on the right track. If not, I'd go back and look at the electrical (bad battery connections or possibly even an dying battery could be the cause.)

Yeah, the battery could be it. The negative terminal was so full of that white powdery corrosion, that I could barely see it. I cleaned most of it off, but did not have time clean the battery post, itself. Thanks for the tip!