Engine not idling properly! someone help!

[brian mcleod]

95 mtx, engine idle is jumping around below 4000 rpm. It will jump from 2000 to 3000, it won't flow smoothly. This is a new problem, started last week.
any ideas???

 

[Rio]

pretty sure u meant 400 RPM's @ idle...4000 is when the secondaries open up for god sakes!

Anyway...Search. There have been many posts concerning this same problem. There is a process to reset the Idle RPM...also this could be pointing to a bad CPS. SEARCH FIRST!!! I just learned this myself... wink

 

[Rio]

pretty sure u meant 400 RPM's @ idle...4000 is when the secondaries open up for god sakes!
Idle should be @ about 800-900 I believe.

Anyway...Search. There have been many posts concerning this same problem. There is a process to reset the Idle RPM...also this could be pointing to a bad CPS. SEARCH FIRST!!! I just learned this myself... wink

 

[RI-SHO]

Are there any sort of new sounds, like a popping?

Have you cleaned your IAB recently? And did the CE light ever come on or is on now?

 

[sdpatt]

I doubt the CPS is involved with this oddity. More likely the idle air control valve or the throttle position sensor. Have you experienced any CHECK ENGINE lights?

 

[brian mcleod]

CE light came on right around the time this starting happening.
No popping though.....

 

[fricker66]

Definitely should pull the codes then. Easy process, check either shotimes.com or do a quick search on this forum. Gotta find out what those codes are before you try to repair!

 

[AutoSHO]

brian mcleod:
95 mtx, engine idle is jumping around below 4000 rpm. It will jump from 2000 to 3000, it won't flow smoothly. This is a new problem, started last week.
any ideas???

Also, after you check your codes, you may want to reset the idle speed to see if that will fix the problem. Do a search for <strong>Idle Speed Reset Procedure</strong> and look for sdpatt's write-up.