I'm about to give up on this fracking idle problem

philip_g

NAXJA Forum User
Location
back in CO
I think the previous thread got lost in the server hiccup.

here's the deal: the jeep wants to idle at 3000 RPM.
to make it driveable I've blocked off the little triangular passage through the throttle body with my costco card :gee: if I remove or unblock that passage, it shoots right up to about 3k RPM.

what I've done:
tried 4 now IAC motors, one of which is brand new
tested the intake charge temp sensor, IIRC it ran about 5k ohms on a 50 degree day, sounds about right
new TPS, adjusted as low as it'll go
found and fixed a few small vac leaks, hoses leaking etc. tightened the manifold bolts I can get to, sprayed carb cleaner all around the manifold and don't think it's leaking or not enough to cause that much of a problem.
sprayed all the other vac lines I can find.
cleaned the grounds, ran a new cable from the (-) terminal to the passenger side of the block, oddly enough I used engine degreaser to clean the connection and must not have cleaned it all off because it wouldn't start after, cleaned some more and it's fine.
flushed the heater core, it didn't help the idle but at least I'm warm now :clap:
I think that's about it. I can't think of anything else but dynamite.
 
I'd tell ya how to fix it, but you wouldn't like the answer. So I'll keep my mouth shut for now.
 
phillip_g said:
tightened the manifold bolts I can get to
So is that all of them or not?

I don't remember, is this with the engine hot, cold, or all the time?

I do remember you saying you swapped out the relays for the IAC. I think the stepper motor is driven by the ECU? If you are just going to throw parts at it, a Renix ECU can be had for less than $50 at the pull-your-shiat. They even have a 30 day return policy.

Edit:
phillip_g said:
I think that's about it. I can't think of anything else but dynamite.
I'll give ya $50 for the heep!
 
all but the back bottom, but a good spray of carb cleaner did nothing so I'm prety confident it's not leaking enough there to cause that much idle, not to mention it idles fine with the IAC blocked off.

it's possible I guess, never know. Maybe I can swap for a few minutes at the house of heeps

it's running rich too, backfiring on engine decel..
 
Hypoid said:
I'll give ya $50 for the heep!


I'm in for $55..........
 
$57.91....all in pennies :thumbup:

AND a piece of leftover Thanksgiving pumpkin pie.:chef:
.
 
Last edited:
philip_g said:
fuckit I'll just buy something else then.
landcruiser here I come. I've wanted one anyway.

So.....



Does that mean you're gonna take my high bid? :D


.
 
........$60
 
If you are blocking off the passageway that the IAC allows extra air to flow around the throttle plate, and the idle is normal, as you seem to imply, it has to be something with the IAC, the t-body itself, or the signal from the computer. Maybe Troys House of Heeps has an extra t-body you can swap out and try. Also, the need to set the TPS to the proper voltage ratio, not to the lowest idle you can achieve.

Fred
 
$61.89 and a whole Pecan pie...We'll even bake the pie for you!
philip_g said:
it's running rich too, backfiring on engine decel..
??? Leaky injectors??? Read the plugs? How old is the EGR valve?
 
Fred said:
If you are blocking off the passageway that the IAC allows extra air to flow around the throttle plate, and the idle is normal, as you seem to imply, it has to be something with the IAC, the t-body itself, or the signal from the computer. Maybe Troys House of Heeps has an extra t-body you can swap out and try. Also, the need to set the TPS to the proper voltage ratio, not to the lowest idle you can achieve.

Fred
I'll check the voltage again but it's sitting around .8.

I haven't thought to actually look in the TB's IAC hole to see if the pintle can't seat for some reason. I also haven't checked the TB bolts but since as you say indicating an IAC problem I wouldn't expect a leak there.

if nothing else PNS always has a ton of XJ's I'll just grab an ECU.
 
.........$70
 
Yer a hard man Troy, a hard man!




















With a good memory.
 
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