offroadXJ1999

So I recently picked up a 99 xj 4.0 2 door 5spd to build up like my last xj I had to play in the trails a bit. Problem is that it seems to be getting too much gas! Only 2 codes read. 1 is battery temp high?! 2nd is oxygen sensor 2. It drives fine but every once and awhile when you stop at a red light for awhile or first start it up, you gotta clear it out because it it wants to die out! its getting too much gas. My first thought would be TPS but wouldn't that throw a code?

Rogue4x4

First code, check the battery temp sensor under the tray. Sometimes the wires get pinched and cause a false reading. Same with 02 sensor, check wiring first, then replace as necessary.

How do you know it's getting too much gas? Verified pressure at the rail?

offroadXJ1999

Thanks for your reply! You can physically hear it getting too much gas it starts spitting and bogging out till you hold in the clutch and give it a few revs and it clears out and drives fine. First thought was TPS but wanted to get opinions before I order it. Would it throw a code? Only does this if you let it idle for awhile so potentially its "loading up" and once you clear it, it sounds great and drives great... Till you let it idle again or first start up

TRCM

too much gas or not enough air

did you check the idle air control valve

offroadXJ1999

Hmmm interesting point sir! How do I check the Idle air control valve?

TRCM

check it ...not 100% sure.

All I've ever done was take it off and clean it out real good, or replace it. Not sure how to 'set' it.

I have had similar issues when mine was dirty, cleaned it, and the problems went away.

I did have to replace it one time tho.....cleaning it didn't help much.

offroadXJ1999

I just cleaned mine and so far so good!! I'll post pics later but it was somewhat dirty. Hard to get off though, it takes a torx and my bolts were so hard to get out due to heat I guess. I'll post a 1 week update and see if my problem disappeared (: thank you all

dave1123

You may find this hard to believe, but the PCM is reading the battery temp as being too low and assuming the air temp is low also, so is setting the mixture rich because if it, plus false readings for the 02 sensor is adding to this misconception.

offroadXJ1999

Any idea on how I can fix the battery code? That does make sense!! Id love to fix it! The cleaning of the idel control valve seems to have helped alot but i have only drove it around town and have a feeling once i get on tbe freeway then stop again it will happen ughh but I got my fingers crossed (:

offroadXJ1999

Before (note how dirty the shaft of tbe plunger is)




After (: nice and clean