Evenexchange

When I drive back and forth from school, my car's RPM generally dip at traffic lights and stop signs recently. My car can be at full operating temperature, and as soon as I come to a full stop (does not matter if clutch is depressed, or the car is in N or 1) the RPMs dip to about 0.5k and then jump back up before it stalls out.

I have run fuel injector cleaner, changed the oil afterwards and nothing has worked. The semester is ending now, so I have time to look into the problem more. I would just appreciate some feedback as to where I can start.

For the record, I have semi-new stock bottom end installed by Ford. The bottom end has about 6,000 clean mostly unbeaten miles on it. I have another 2 years left on my warranty, would they maybe take my car and fix the problem?

Evenexchange

Might I also add, that I took apart the air intake assembly and cleaned the filter that is mounted in the fender. I actually took the filter out, and it was already clean... but I used compressed air on it anyway and cleaned out the minimal amount of dust that was in there. The problem still exists. Might it be time for a throttle body cleanse?

LynnBob Mustang

If you got a warranty left on your car I would take it in and let them worry about it.

Lynn

devongarver

it may seem silly but the first thing that comes to mind is your AC kicking on and off and it temporarily knocks down the idle.

But really what im thinking is its your IAC taking a **** on you. Very common. Take it off and clean it with some carb/choke cleaner and stick it back on and see how that goes for ya.

mustangman03

your airfilter is it like a K&N style filter also try unplugging the MAF sensor and see what it does

Big Top Gt

I'd also look to see if any of the hoses have come unhooked or maybe the rubber couplers aren't sealed right.

The symptoms you're experiencing could also point to unmetered air getting in somewhere.

ChalknCover

I recently had that problem of the rpms dropping at stop lights and signs, I hit my MAF sensor with some cleaner and now works great. May wanna try that as well. If all else fails, take it to the dealer since you still have a warranty.

mestit3

sounds like iac to me.

mustangman03

The dealer wont warrenty it that was on his shortblock he had put in not on the rest of the car

AirBrontosaurus

Yep, sounds like IAC. Give it a clean and see how that works.