My 2002 non type s has started with a strange issue. It has been parked for about 6 months as I was out of the country, but it was started at least every other month at minimum. During those, months they would start it and just let it idle in park with no issues. Now when I start it, when in park and neutral, it will increase in rpms to about 2k, then drop to 500 and then repeat. When I put it in drive, it idles normally. I did have to jump start the car and as soon as I turned it off, my battery died again and the dome light did not even work. Does this sound more like a power management issue (battery) or a fuel system?

 

Hey Fellglenn, our TL's don't like sitting around and not being driven regularly.

Chances are that something is maybe sticking or gunked up. A lumpy idle could be simply caused by old or bad gas. Try some fuel system cleaner and top the tank off with some premium high octane gas for starters. As always, check the vitals such as the coolant level, oil and etc. It would be a good precaution to have the electrical/starting system load tested at any local auto parts store for free. Any CEL ?

So 1st: New gas and FI cleaner. 2nd: Check electrical charging. 3rd: Clean IAC valve and EGR passageways, along with TB intake. 4th: Run it like ya stole it !!!!! Good luck, man.

 

sounds like IACV and egr passages in manifold are crudded up
happens more by running car short times
easy diys

 

I'm agreeing with the IACV solution. Similiar scenario with being undriven for 6 months and then an oscillating rpm when idling. Cleaned the IACV with no improvement. Replaced the IACV and worked like a champ.