NewKindOfClown

FIFY

MarkMelicia

hey guys,
need some advice. 2001 xj getting the follwing codes,

po123: idle position sensor high voltage, po505: idle air control motor circuit shorted, P0130: upstream O2 sensor heater relay circuit fault, PO136: downstream 02 sensor heater relay circuit fault, P1491: radiator fan relay circuit open or short, P1596 speed control switch always high.

airbag light coming on intermittently. running ok other than a bucking/misfire when accelerating.

where should i start in troubleshooting.

thanks

cruiser54

That's way more accurate!! LOL.

rickeyj99xj

Okay so I've been having this problem on my 86 Cherokee 2.8l 5 speed. When I get in in the morning it'll start then shut off. Then start back up and stay on but when I put it in 1st to pull out I bucks and wants to hesitate with a little driving it goes away about half way to work which is about a 20 min drive any idea? I know the idle needs to be turned down a little I'll be doing that tomorrow. But I have no idea why. Also I'm going to be putting a new fuel filter in. Any help would be appreciated.

ITTs_Cole

SO before i knew anything about vehicles when i got the jeep and did my first oil change i treated it with some sort of stop leak. Ive changed the oil a few times since then for whatever reason. (its gotten 3 oil changes in under 10k miles) Will seafoam in the crank case help flush all that crap out?

HappyPappy

Yep, but I would advise using Motorkote in it after that along with Shell T-6 synthetic 15-40 oil. I,ve used it in mine, but the motor was toast anyhow. READ the directions on the can. Left mine in for a couple hundred miles or so.

jeeper albert

A man claimed his MJ had a chassis.
I thought XJ's and MJ's both were unibodys.
Could this be true ?

salad

Chassis means a lot of things. XJs definitely have one.

MJs are uniframe up front and real frame in the rear.

NewKindOfClown

Yes. More specifically, it's a hybrid with a boxed frame in the rear and a removable bed.

Wolf427

Ran a compression test on my XJ today, really low compression on a couple of cylinders, 40PSI low. I did a wet test and it didn't change the numbers much, so I'm assuming its my valves. I remember when I took the head off, I could push tons of water through with just a garden hose.

Am I better off buying a new head, or doing a valve job?

cruiser54

Get a price from a local machine shop.....

DieselD

What bulb does the stock switches (defrost, aux lights, wiper) use? I want to put LEDs in them.

Cherokeekid4x4

Fuel pressure test at idle. With the vacuum line still in was only about 34 psi which dropped when I hit the gas. Once unplugged my pressure was at a steady 40 psi. Thoughts?? I'm not sure what's the correct psi it should be at. Also how long should te pressure hold after engine is turned off?? It held above 30 for more than ten minutes. I then unplugged the gauge.

cruiser54

0 to 20 psi drop in fuel pressure after running/shut off/waiting 30 minutes.

31 at idle and 39 with vac line off for the first test.

Cherokeekid4x4

Okay why are some 4.0s supposed to be at 49 psi +\- 5 psi? Mines a 94 if this makes a difference.