Up and down idle???

[jakef7]

Hey guys, my car is idling really weird. Its up and down up and down. Its driving me crazy!!! Sometimes it almost stalls out on me. The only thing I have done to the motor is intake/tune. I called the guys at Brenspeed and they suggested that I clean my throttle body. I did that and still no change. When I turn on the AC it gets even worse. Does anybody out there know what might be causing this? Really would appreciate the help.

 

[Az Pete]

Go back to the stock tune and see if it continues. If it continues, leave the stock until solved.....If it is not there, go back to Brenspeed with the problem.

The A/C on only creates more of a load on the engine causing the change to seem more drastic. Any codes?

 

[jpplaw]

Look for a vacuum or air leak somewhere. Check all the CAI connections.

 

[jakef7]

I might just put it back to stock and take it to ford. If it quits after I switch it to stock I'll get back in touch with Brenspeed, though they said they have never have had an idle problem with their tunes. Anybody else???

 

[jaybertx]

Bad coil pack maybe? I had that issue with my '01 and that's what it ended up being.

 

[Rhymhoont]

Bad coil pack maybe? I had that issue with my '01 and that's what it ended up being.

This is exactly what my 02 F150 did and after a few months it started to miss sometimes at very low throttle at 60mph. It FINALLY gave a warning light, and it was a coil pack. After 160,000 miles I have had to do this 3 times.

See if you mechanic can find a code that may or may not be saved in your computer.

 

[2faststangs]

Same thing is happening with me now. Started after i loaded my BBR tune, stopped when i returned to stock. The problem is in the tune, contact Brenspeed and tell them you want another tune written.