I have a '97 xj. 4.0 litre 4 wheel drive.

The problem started when I started it one day and thirty seconds later it died. It kept doing this until I changed the coolant temp sensor. After changing that it stopped dieing, but it still sputs, stutters, and bucks when I try holding it at a constant highway speed. Accelerating is a pain too because it seems to just keep missing.

I've changed:
-Coolant temp sensor
-Upstream oxygen sensor (needed it anyways)
-Crank position sensor
-Cam position sensor (which got rid of the p1391 code I had)

I am now beginning to think that I have a fuel issue? It will for the most part idle fine, but seems to bog down when under load. Anything you guys would recommend? Everything I have tried hasn't cured it. Thanks!!

 

So there are no codes now?

If there are, you MUST follow the lead of the code.

If there aren't any codes, then testing fuel pressure at the schrader valve on the fuel rail is absolutely your next step.

For yours, you should have 49 psi at idle, plus or minus 5 psi.

Good luck and post back what you find!

 

I took it out and drove it for about fifteen minutes and it never came on, before that it would come on fairly soon so I am assuming all of the codes are clear.

What would I need to check the fuel pressure? I will probably give that a try next weekend

 

Check your idle control motor.. Give the throttle body a good cleaning and check the tps while you're at it..

 

how about the spark plugs have you checked them

 

Haven't checked the spark plugs. I did a whole tune-up about a year ago, but that's probably worth the check. I like the idea of checking the throttle body too. I'm making a list of everything suggested! I'm sure it's something that's not major, just annoying

 

All you need is a fuel pressure gauge. You can rent one from many big box parts stores for a few bucks.

It attaches to the schrader valve on the fuel rail (looks like the valve on a bike tire).

Fuel pressure is something that would be tested very early in the process at any shop.

Do this.

 

Will make sure I pick one up next weekend! thank you