1988 XJ motor problem

Post by **Ctrow** » Tue May 25, 2010 2:55 pm

Heres the deal:

I'm in the process of getting Adams jeep ready for it's new home (his house instead of mine), and it is having trouble getting up any kind of hill or incline. it's a 1988 xj with a 4.0 and 5 speed. When you are on any kind of an incline such as my drive way, it starts to bog down and will stall its self out if continue to give it more gas. This being said, if you put it in 4 wheel drive, it still seems to have some trouble but will make it make it up the driveway. My initial thought is clogged cat, but I don't know why it would make a difference in 2wd or 4wd if that was the case. Just wanted to see if anyone had any ideas before I start pulling the exhaust apart. we all know how much fun rusty bolts can be. Thanks

Post by **Stinson** » Tue May 25, 2010 3:55 pm

excuse my jeep ignorance, FI or carb?

Post by **Arya Ebrahimi** » Tue May 25, 2010 3:55 pm

All 4.0's are FI

Post by **hklvette** » Tue May 25, 2010 4:27 pm

vacuum leak? That would be my guess since engaging 4wd (and I assume the CAD vacuum) makes a difference.

Post by **Arya Ebrahimi** » Tue May 25, 2010 4:32 pm

Holy crap, Henry just contributed a valid possibility!

Post by **Ctrow** » Tue May 25, 2010 5:08 pm

I did a rough inspection for vacuum leaks and didn't find anything. My experience with vacuum leaks is that it will run rough at idle, which isn't the case here. Thanks for the idea tho, i'll do some more looking into it.

Post by **Arya Ebrahimi** » Tue May 25, 2010 5:11 pm

How about the theory that the motor mounts are shot and when you're putting a load on the drivetrain it torques over and messes with either a vacuum line or an electrical harness? Does it do it when you floor it on flat ground?

Post by **Ctrow** » Tue May 25, 2010 6:01 pm

Arya Ebrahimi wrote:How about the theory that the motor mounts are shot and when you're putting a load on the drivetrain it torques over and messes with either a vacuum line or an electrical harness? Does it do it when you floor it on flat ground?

does have a shot motor mount. I'll try the flat ground thing. In addition i just remembered that I wedged over the axle actuator fork and plugged the vacuum lines that would normally shift the fork a long time ago. Not sure if that makes a difference in what Henry was saying.

Post by **hklvette** » Tue May 25, 2010 7:33 pm

a test i've heard about is using starter fluid (or carb cleaner) to check for leaks. with the engine running, lightly spray any suspect lines. If the engine flares up at any point, there's a leak pulling in the spray.

Post by **alk1174** » Tue May 25, 2010 8:58 pm

hklvette wrote:a test i've heard about is using starter fluid (or carb cleaner) to check for leaks. with the engine running, lightly spray any suspect lines. If the engine flares up at any point, there's a leak pulling in the spray.

An unlit propane torch is supposed to do the same thing.

Post by **hklvette** » Sat May 29, 2010 9:37 am

any luck with this thing?

Post by **Fonger** » Sat Jun 05, 2010 9:31 am

Does it misfire or just bog down? If it's a misfire I'd say check your timing. If it is bogging down check your fuel filter and quality of fuel. If this thing has been sitting the fuel can get funky pretty quick and really foul things up.

Drain/siphon the tank put in a crap load of Sea Foam and 91 octane, change the fuel filter and try again.

Post by **Ctrow** » Sun Jun 06, 2010 8:46 am

I found oil in the distributor cap and it looks pretty chewed up. I think it needs an all around tune up. At this point I got it set up with a towbar and I'm planning to tow it back it to my bros house. From there the plan is to go through it, make a list of everything it needs, and determine what we want to do. I'm about to pick up a 96 5-speed and we might do some parts swapping instead.