Where else to look for idle issues.

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dyna

NAXJA Forum User

Location

central coast Ca

• Jun 14, 2006

• #1

I posted regarding my 88 MJ 4.0 5spd was having idle issues. It will idle for several minutes at 800 then go up to 1300 and stay there for a while then come back down after driven at speeds. I took it in today for smog and it passed, they adjusted the TPS and said it was OK now. Now it hauls ass like my HO 95 but still has the idle issue. Ive checked for vac leaks and none found. any ideas. They mentioned a servo motor possibly?
Thank You.

 

P

Phager

NAXJA Forum User

Location

Corvallis, OR

• Jun 14, 2006

• #2

Have you cleaned the Idle Air Controller and it's passages? It's located to the left of the TPS on the throttle body. I had an idle issue on my '87 MJ and scrubbing the IAC with a toothbrush and some TB Cleaner took care of the issue for me.

Hope this helps,
Pat

 

D

dyna

NAXJA Forum User

Location

central coast Ca

• Jun 14, 2006

• #3

Im gonna check the TPS detting again when I get home and Ill chack that also.
Thank You.

 

D

dyna

NAXJA Forum User

Location

central coast Ca

• Jun 14, 2006

• #4

Im gonna check the TPS setting again when I get home and Ill check that also.
Thank You.

 

Matthew Currie

NAXJA Member #760

Location

Vermont, land of big clay

• Jun 14, 2006

• #5

Check for idle problems with the linkage disconnected from the throttle body. I had throttle linkage problems with my 87 that had me running around in circles checking TPS, IAC, etc. etc. when all the time it was a stiff accelerator pedal pivot. Later the problem came back with a binding bell crank.

 

X

XgeekstarX

NAXJA Forum User

Location

winter springs, florida

• Jun 14, 2006

• #6

the idle air controller stops being used the second you give it any throttle... the TPS comes in to play. if you look at the throttle body you'll see an air passage on the top of the butterfly and on the bottom. the idle air controller motor regulates the amount of air let through that passage at idle. most of the time they just get gunked up with dirt and you can pull them out and clean them.

 

D

dyna

NAXJA Forum User

Location

central coast Ca

• Jun 14, 2006

• #7

Guess I should have listened the first time. I found a vacume leak. Fixed it and now it runs great.

 

C

carnuck

NAXJA Forum User

Location

seattle

• Jun 14, 2006

• #8

Was the leak in the line going to the MAP sensor? (little black box on the firewall) Another fun thing is when that hose clogs up and messes with the signal. I clean mine out at each tuneup (it's amazing the crud that comes out!) and gas mileage stays at @20 mpg (with 33" tires, 5 speed pukeout trans and 3.73 gears with a 220,000+ mile engine)