Trottle Body adjustment - 1989

My '89 Jeep's throttle Body is out of adjustment, apparently. My mechanic can't fix it (and the software is not available in my city). He has suggested a new T. Body.

Problem: when the truck is warm (only when warm) and I brake, the RPMs fall below the 500 and the Jeep stalls. You have to double foot it to drive it.

Can anyone give me an idea of how to fix this? Could it be the TPS (throttle positioning sensor)?

thanx a lot.
tad.

Are you sure that's it? Seems like it could be vacum leak to me.

I don't know if it's a vac. hose. However, the story is: I had a new fuel pump/send unit and injector "o" rings replaced about a week before this problem started. Now, my Jeep's at a different mechanics (who comes highly recommended for his diagnostics ability)...

As I understand it, it's pretty hard to reset the t.b sensors w/o the dyno. software. I really don't know what to do?

tad.

unplug your egr valve and see if that makes a difference. It could be opening to soon, makes for bad idle.

How do I disconnect the ERG?

Isn't it needed to regulate back pressure / emmissions?

thanx.

If you can do some basic troubleshooting and can use a multimeter, I suggest you get a Haynes or Chilton manual. Check your power brake booster. It sounds like it may be leaking.

the egr valve is needed for emmisions, how ever, when the jeep is warmed up, if you disconnect the vacum hose going to the egr valve and it solves the problem, then replace it. Its a possible and very fast to test, may as well try it, I had the same situation before.

the egr valve is needed for emmisions, how ever, when the jeep is warmed up, if you disconnect the vacum hose going to the egr valve and it solves the problem, then replace it. Its a possible and very fast to test, may as well try it, I had the same situation before.

Is the ERG hose from the valve cover to the breather box? I guess I should pick up a manuel, right.

thanx.

My Jeep is going in the shop tommorrow morning for the very same problem. I'm getting the throttle body error code through the key on/off flasher. EGR problem shows up as well, but the symptoms don't really resemble a egr problem, which I have had before. Been intermittent, but stalls sometimes when it idles down bleow 500 as well.

I'll let you know what the results were when I get it back, hopefully tommorrow afternoon.

What about the AIC valve? Might try taking your TB off the Jeep, take it apart and clean it, could just be carbon build up. Also get your fuel pressure checked just to rule out the pump seeing how this happened after it was installed.

For the EGR vacuum line, look between the airbox and the intake manifold, there is a round disc looking item bolted to the intake(has a little rod going into the intake) This is the EGR valve. Just unplug the vac. line to see if it goes away.

My Jeep is going in the shop tommorrow morning for the very same problem. I'm getting the throttle body error code through the key on/off flasher. EGR problem shows up as well, but the symptoms don't really resemble a egr problem, which I have had before. Been intermittent, but stalls sometimes when it idles down bleow 500 as well.

I'll let you know what the results were when I get it back, hopefully tommorrow afternoon.


Just got mine back, my mechanic repaired the tps sensor connector, and that took care of the idle problem.

Just got mine back, my mechanic repaired the tps sensor connector, and that took care of the idle problem.

thanks. I'm gonna pick it up from mechanics and take a look myself tommorow.

Even though the Cherokee idle is not suppose to be adjustable it can be. a pair of needle nose plyers and turn the adjustment up to bring up the idle.