90Mustangfan

Ok the car is an 89' 5.0 with a comp cams cam, and full exhaust 3.73 stock heads and intake manifold....I dont know the specs of the cam but heres the problem...when you first start up the car it idles fine, vaccum is fine everything is perfect...but when the car gets warm or has been running for about 30min, the idle will start surging...ie.. going from 600-800 or so rpm...whats causing this...the cam is pretty radical...nice lopey idle.

Quik

if its only moving from 600 t0 800 i wouldnt worry about it

90Mustangfan

I know the computer is searching for a idle and thats why its bouncing, but what can you do to fix it? will a custom tune fix that?

Quik

you got a cam with stock parts. i wouldnt worry about a tune, i would mess with the idle screw some, timing, TPS and try that IAC mod