Battle Max

Wondering if someone can help me pin point the problem. When my AC is on the idle dips up and down when at a stand still. Yesterday while coming to a stop at a light the rpms dipped so low it killed the car. Anyone have any ideas?

rshamekh

If you have a tuner try to bump up the idle rpm.

Otherwise, dirty throttle body or maf sensor.

GidyupGo

The rpm is supposed to go up and down with AC on. Lets you know the compressor is working.

hammeron

i just read about this recently in the
manual....

when you turn on the AC, the PCM is supposed
to receive a signal, then raise the rpms
to compensate for the load. it sounds like the
PCM is having trouble regulating the new target
RPM

like others have said, it might be a good idea to
clean the MAF and throttle body....those are the
items involved in idle control

lrgnation

My car has occasionally done that it has never died though. I have heard of other people's doing the same thing though.

chabbz182

Yeah it happens adjust your tune.

actfastus

Yes, I have had and now have the same issue on my 2005 GT. I put on a new no tune CAI last year and the car didn't run well. I put the factoryfilter back on and it got worse. I took it to the Ford dealership and they said I needed a new throttle body....thank goodness under warranty. After that, it ran great but stayed with the factory filter. But recently, I put in a new battery and lost the factory tune. On page 199 in the owner's manual, it shows how to "re-learn" the proper idlefor the car. I tried but did not work. I also get the CEL error light. I guess I'm going back to the dealership. Try the owner's manual. Apparently, there are a lot of little things like that in manual. Good luck!

Tango and Cash

I replaced the battery in my 2005 GT (Texas heat fried it!) and I'm now getting a slight surge at idle (50-100 rpm), along with a lower-than normal idle (was around 700, now closer to 500), with the car in drive and a/c on. It seems to come and go, sometimes the surge is more pronounced than others. Actfastus, I'll get out the owner's manual and try the "relearn" process...

Tango

MikeTrimnell

Did you ever figure out the issue after your battery died and the car was surging, what did you do to fix it please. I am at my wits end, I relearned it, calibrated the throttle, the TB is very clean havenet sprayed it but no build up. Any help would be appreciated.

Mike

JC Martinez

If anyone is having this issue they can find relief knowing I resolved this issue by cleaning my throttle body and MAF sensor. Just a couple of minutes taking apart the pieces and cleaning them did the trick. Texas air is so dirty that it can tend to clog up your system and cause your car to shut off while idle or have trouble while accelerating. I've been trying to figure this problem out for months. I hope this helps and saves you a lot of money from going to the car shop!