'99 Dodge Grand Caravan Please Help with Rough Idling

[goingtocarolina]

Hi,

This is my first post and am hoping someone can help me discover our problem.
We have a '99 Grand Caravan that has been idling rough for about 2 months now. We've taken it to 2 different mechanics, one cleaned the throttle body the other said it is probably the fuel filter, so changed that, so far nothing has helped it. It is not throwing a code so they can't hook it up, and they now tell me to wait until it stalls, then it Will throw a code, and they'll know what it is.
When it's idling rough you can actually feel a "bumping" in the seats like it's not getting enough oxygen or something. The one mechanic says that it is probably the oxygen/fuel relationship but won't say that he can fix it. I don't want to wait until it stalls and I have my daughters in the car with me and I'm 50 miles from home, can someone please advise me on what we should be looking for next. We've tried the carb cleaners in the gas and it just passed inspection in June, so don't think it's a spark plug problem, any advice at all please!

[yogi_123rd]

Concerning rough idle in caravans: while spark plugs can last for 3 years, the other tuneup components - distributor cap and rotor, do wear and only last about a year. Cracks or resistance and build up in the caps.

I also assume you don't have a bad spark plug wire, but that's also a possibility.

Also, the carb cleaner put into the gas only cleans the fuel injectors. The real area (as far as a bad idle is concerned) that should be cleaned is the throttle body where the idle "motor" is located. Remove the air intake hose to the throttle body and using a can of carb cleaner ($3.00) spray the stuff directly into the throttle body (past the butterfly valve) Also, into any holes you see on the inside bore. There's a small hole before the butterfly valve that is an air bypass for idle control. Carbon deposits will build up from the PCV valve and get all thru the inside areas. It will surprise you to see all the black soot that comes out.