chinto

I'm new to jeeps and am trying to get an 01 on the road for a winter vehicle for my wife. My frined that owns it let it sit for so long that things seem to be seized up.

Originally he thought all it needed was the alternator replaced as it was siezed. I pulled it and had it rebuilt, and we managed to get the motor fired, but it will not stay running without pushing the gas pedal. As soon as you take your foot off the gas it stalls. It could be that the fuel in it is about a year old (not stored with stabilizer either).

Also while it runs there seems to be a loud rattle or knocking sound that appears to be coming from the AC compressor.

Any thoughts on how I should proceed?

thanks in advance for any help.

finneys98xj

cps, tps and some high grade gas.

chinto

cps?

I am assuming that TPS is throttle position sensor?

JeepCoMJ

don't forget the new fuel filter.

I'd think the CPS should be fine, and the TPS would probably need the most attention.

also, new plugs, wires, cap, rotor, oil filter, and oil change are things I would do.

JeepCoMJ

CPS is the crankshaft position sensor, and you're correct on TPS

finneys98xj

fuel pump should be fine just run a good cleaner. like Seafoam

JeepCoMJ

correct sir,

I meant filter but was thinking pump for some reason

I wouldn't run old gas either unless adding a stabilizer...you could siphon the fuel out of the tank, burn it in something else (say, you're lawnmower), and run high octane in the xj for one tank. xj's seem to run better on 87 octane or mid-grade octane.

finneys98xj

my xj ran great with hiogh octane.

milmat1

If it's able to run thats a Plus + Get some good fuel and some fuel system cleaner and run through it.
Also check for intake leaks ! Spray some carb cleaner around the Gasket area while its running and try to locate a spot that causes a change in RPM.....

okcjeeper

Also look at vacuum leaks. may sound weird but a major vacuum leak could cause it not to run at idle..

chinto

some cleaner and some fresh gas got it running. There seems to be a knocking sound coming from the AC compressor. I loosened the belt and the pully on the compresser is vey loose. Should it be so loose?

finneys98xj

no replace before it flys apart and you have a big problem

chinto

do I need to replace the whole compressor? Or can i just replace the pully and bearing? I have never had to replace an AC compressor before, I would imagine that is a job that a professional should do, with it being pressurized refrigerant and all.

JeepCoMJ

I'm sure it ran just fine.

however, there are verying opinions on the optimum performance achieved from the different octanes, and it's general consensus that the 4.0 seems to run better with less issues when you run the factory recommended grade of fuel, or mid-grade fuel.

remember, the 4.0 is not in any way a performance motor...it performs great, but is designed to run off of cheaper fuels.

BlueXJ

Yes the clutch can be replaced but again it should be done by a professional. I thing the system needs to be evacuated of freon to change the clutch because of a seal or o-ring which is on the shaft. Not too sure I had my whole compressor changed and converted to R134 at the same time.