Any way to lower idle without a tuner?

Discussion in 'Fox 5.0 Mustang Tech' started by Bigstang1, Aug 16, 2006.

  1. My 89 has a b-cam and 1.7 rr that i installed over the winter with crane valve springs. The springs were tired after 180k miles so i put the cam and rockers in at the same time since i got a good deal on them. Anyway, i'm having problems getting the idle where i want it. I have the idle screw almost totally closed with the tp set at .98v. and i still cant get it any lower than abo9ut 1000rpms. i had the timing at 10* and it was at about 800 which i could live with. recently i bumped base tioming to 18* (no detonation) and obviously that raised the idle. is there any way, without a pms or tweecer, to lower my idle back to about where it was? I heard somthing about a plate that goes betyween the tb and iac but cant remember what the guy said. thanks. ooo and if you could spare me the flames about a cam in a stock motor i would apprieciate it cause ive heard enough lol thanks again.
  2. See "Help me create the Surging Idle Checklist" at
    for help with your idle problems. The first post contains all the updates to the fixes. I continue to update it as more people post fixes or ask questions.
  3. If you have the idle screw backed all the way out, and the idle air controller unplugged and your idle is still at 1000rpm i'd check the vacuum. A leak would let more air in like an open idle air controller would... causing idle to go up.