Excessive high idle speed

1997 MITSUBISHI MONTERO
223,000 MILES • 6 CYL • 4WD • AUTOMATIC
Avatar
JOSE BRANDI
  • MEMBER
  • 15 POSTS
Hi,
My montero '97(3.0 - 12 valves) have a high idle speed(at start 1500 rpm and increase maintaining in 2,000 rpm. No sound is detected from the IAC (idle air control step motor). This device could be damage? This malfunction arose inmediatelly after cleaning the throttle body and timing change. The valves are open, leak or bend? With the key in on position and stop engine the load value is in 78 % is supose to be on 0%. No OBD II codes area shown. What happen? How may pinpointing the fail?
Jan 7, 2011 at 3:25 PM
Advertisement
Avatar
JOSE BRANDI
  • MEMBER
  • 15 POSTS
Clarification... timing belt change
Jan 7, 2011 at 3:27 PM
Avatar
MMPRINCE4000
  • CERTIFIED EXPERT
  • 8,548 POSTS
Recheck the timing belt marks, if advanced too much it will idle high.

But for the most part an idle that high is a vacuum leak.
Jan 7, 2011 at 3:30 PM
Advertisement
Avatar
JOSE BRANDI
  • MEMBER
  • 15 POSTS
Thanks!!
Jan 7, 2011 at 4:03 PM
Avatar
JOSE BRANDI
  • MEMBER
  • 15 POSTS
I foget one detail. After the timing belt installation, I start the engine with out connect the throttle body hose tube. This action could incorrect lern the PCM? And set incorrect IAC value?
Jan 7, 2011 at 4:14 PM
Avatar
MMPRINCE4000
  • CERTIFIED EXPERT
  • 8,548 POSTS
Yes.
Jan 19, 2011 at 3:46 PM