I was told that part of my rough idle problem may have to do with the air/fuel mixture screw on top of the throttle body. Mine is sitting just a hair above being flush with the casing. I've had 2 different people tell me that they have never seen one screwed out that far. they say it is usually about 1/8" down inside the casing. Is there a certain number of turns out that these are usually set to?

 

Its just used to set your idle, what are you idling at now?

 

really? i was told it does more than that. Its idling very high right now. I just hooked up my new dash with tach but havn't ran it yet to see the actual rpm's yet. so that controlls the idle and not the stop screw on the side of the tb?

 

yeah the thing on the side is for the dash pot to bring the motor down slower from a high rev. Turn your idle screw down and if your motor is stock it should be around 750rpm and see if that helps!

 

the set screw on the throttle linkage is only used to set the initial throttle plate position. it's adjustment also can affect the throttle position sensor.
the screw on the dashpost is to set the amount of dampening the dashpot puts on the throttle during deceleration to prevent backfiring and other issues.
the screw on top of the throttle body only allows air to bypass the throttle plates thus controlling the idle speed.

 

thanks. I've learned so much these past few days from this site. Maybe one day i'll understand what that little Japaneese guy was thinking when he was designing these things.

why cant all vehichles be designed like Jeeps? Uh oh, might have just said too much...

 

 

Cause then none of them would runn....

 

easy now... you guys should have known i was a jeep guy by reading my screen name....XJ...

Thats alright, i actually own more yotas than jeeps right now. And they both ride down the road better than the jeep.

Thats actually why i bought my 89 last week, to quit driving a lifted cherokee on 35's and locked f/r; on the road everyday. Not to mention the fuel savings

 

well, once i got my tps set right i tried screwing with the idle screw. I had to screw it all the way in to get my idle around 900 Is this normal? Should there be anything under the screw like a spring or something? There wasn't anything under it but looked like a spring should go in there.

 

the idle screw on the throttle body is similar to a needle valve. it just protrudes into a passage to restrict the airflow the more it's screwed in. no spring, but I believe there's an o-ring that goes around it.
and is that speed with the engine warmed up or cold?
did you re-do the timing?

 

its warm. I have to pick up a timing light and check it.

 

by the way, here is the truck in question.

 

It is no accident that "Jeep" is a four letter word.

 

oh nice one!

 

the timing was real high. I set it to 5deg. with the diagnostic ports jumped and with it unplugged it is at 12. Thats right about what the write up i read said. seems to be running smoother now. I still have the idle screw all the way in to keep a nice idle.

 

I have not come across a 22re that requires the idle screw to be all the way in. Maybe a previous owner has adjusted either the throttle plate stop screw or dashpot to hold the throttle open, thinking either was the idle speed adjuster?

 

that could be the case. I'll drive it around tomorow and see how she does. right now its idleing right around 800 when warm but thats still with the screw all the way in.

I'm just glad the sputter is gone.