Tugby

Any6 one experienced this idle problem after a few mods?

92GreyGT

Yes. I built a 331 with Trick Flow street intake, AFR 165, and Trick Flow stage 1 cam. A buddy had a stock car that ran fine so he and I would swap parts to see what was bad and nothing helped. So I wrote into MMFF and they said to drill a 1/4" hole in the throttle body blade. It worked great, the car idled smooth and I had no more trouble until I changed cams to the Comp Cams XE 274 HR. Now I'm back to square one. I even bought that plate that goes between the throttle body and the IAC and that helped a little but didn't solve it.

mustangmike33

what deos this plate do? the one between the IAC and the tb

crusin92red5.0

i have the same problem with my car after mods, it seems pretty familar.

here is a link to another mustang site who made a pretty good right up to hunt down idling issues, it really didn't help me, but it might help you.

link

JZTRK

Try this
http://www.fordmuscle.com/archives/2...in/index.shtml

topless91gt

I had the idle surge after my h/c/i swap. try cleaning the maf, iac and throttle body. then reset base idle and check tp voltage

Joel5.0

You need to go through the pinpoint and diag procedures to ID what is causing your idle control problem. Anything from a code 67, A/F trimming, vacuum leak, wrong/faulty MAF, wrong PCV setup (open system instead of closed... causing unmetered air issues), wrong initial spark timing setting, faulty IAC valve, wrong base idle setting, too much lifters preload, any other EEC failure code. Suggestions?

- DIY KOEO/KOER self tests procedure (fix any failure codes)
- Base Idle Reset (no need to set the TPS to any mythical setting BTW)
- Check/Calibrate initial spark timing
- Make sure the distributor is not one tooth off
- Check for vacuum leaks

LUK