There are a lot of possibilities that can cause issues at idle. The first things to check are the cap and rotor, (unless your car has a coil box and does not use a distributor), plug wires and plugs. If there is any question, you should replace them all because they are part of a regular service anyway.
Then there are electrical items that might be at fault. That is part of the challenge with electrical stuff as it will fail slowly, intermittently and in all cases, totally. It can also be an issue where one weak part makes another fail. Overheated electrical will put demands on dependant components and can damage them. I have fixed stuff and had other stuff fail at a later date due to aforementioned situation. So, it is best o go through a process of elimination, but use reason when a part failure can damage other parts when it catastrophically fails.
Before you replace anything, let me know how the plugs look.
Pull the plugs when you get a chance and look at the tip. A brownish tan color is normal. If you find anything else. Let me know what it looks like.
The next step will be running a can or 2 of injector and intake tract cleaner. This is the issue for many fuel injected cars having performance an idling problems. I use BG44K as it is the only cleaner that I have found that truly cleans the injectors and intake tract to the pint where even injectors near failure can be saved. You might have to go to a service station or car dealership to find it as auto parts store do not always carry it.
Saturday, October 16th, 2010 AT 7:55 PM