I have been searching google and forums for a week searching this. 2000 xj sport 4.0. Stalling at idle and when removing foot from gas going down a hill. It is a newly rebuilt engine. New cam, crankshaft machined, cylinders bored .30 over new pistons, rings, bearings, head. New radiator, waterpump, thermo, tranny fluid filter flushed and changed. New camshaft and crankshaft sensors (mopar brand) new champion platinum plugs, iac and tps replaced last year, theottle body and iac cleaned out. It has thrown camshaft position sensor cel through two new camshaft position sensors over the past year. At a loss....any ideas?

 

Does it do it's fast idle when started cold?

 

No. It idles between 700-800.

 

I am thinking of having battery load tested at autozone. I believe it should be at like 14 or 14.5 to be considered good for the jeep. I am also going to start going through all grounds although they all got a good solid connection when i reinstalled the engine. Trying to think of common parts between the old engine and the rebuilt engine. Some common items...battery, fuel filter, wires. Will try to think of more. I really want to drive this thing!

 

Mine idles up for an instant and then settles to about what yours idles at.


Beings you'll be at AZ get them to do a complete diagnostic on the vehicles. Had mine done last summer at Advance Auto for free.

 

Oh. Do they just plug it in and check the computer? See what it says? I guess it is not autozone. That one has no garage. It is advance auto zone

 

Its large handheld unit. No garage needed. You'll also get a print out. Auto Zone here does it.

 

Oh awesome. I will have them do that at autozone. Its across the street from the advance auto parts

 

If you rev the engine will it rev up out of the stall, or does it just stall out regardless?

 

Have you done a thorough throttle body cleaning?
Have you confirmed proper Idle Air Control (IAC) operation?

 

I can feather gas and keep it from stalling yes. Theottle body, iac, and iac housing cleaned super thoroughly.

 

I take back the idle observation of 700-800. I was incorrect. It is actually low. Between the first and second line. Taht would be what like 400?

 

If you get a multi meter you can test your IAC.


IAC ohms test:
Pin sequence;
A B C D
A to D/B to C = 40 to 80 ohms
A to B/C to D = open

 

I stole ^^ that. Same for Renix?

 

GOOD! Now I'll know where it's at when I need it.


I got the specs for the test from an engineering site a few yrs back. Lost it in a computer crash. They never gave any brand or vehicle specifics but the ohms values given are what I got when I tested my new one and what I didn't get from my old one. I'm going to be pulling the one off the wife's Blazer soon and plan on testing it.