If hitting a pothole is able to knock your motor out of time, you got some major problems. I'm calling bull scat on this little bit of advise.
And a vacuum advance on a 91 XJ? Don't have one.

Has the fuel filter ever been replaced on this 91 XJ?

 

so i cant check a vacuum advance on mine?


i just wabt to know what can cause this....

 

There is no vacuum advance on your rig. You may have the firing order off, the fuel filter could be clogged with crap, it could even be the CPS.

 

i checked my firin order and i did what the internet told me,but it wouldnt let it start,so i rotated the plugs clockwise and it cranked up within 1sec. i just replaced my fuel filter and it ONLY misfires when im acceleratin,im goin to clean my TPS and is ir possible to clean the CPS and O2 sensor? if so how do i do it tight

 

Can't clean the TPS, the O2 sensor won't cause a miss under load, and you can't clean the CPS. It has to be either an ignition system problem or a fuel problem.

 

Is it possible that you might have broken a fuel injector wire??? You never know...

 

K, take it easy there bulldog... I didn't know about the vacuum advance on the 91... I told him to check and see if it had one... I knew my brother's 85 CJ has one on his 4.2 and my 91 s10 had one... I was just throwing it out there for him to check on it... in case it had one... I've never had the problem on mine, do I didn't specifically know whether the 4.0 had one or not.... as far as the timing being knocked out from hitting a bump... it happened to my boss in a 80's model f-150... her truck had a lift and 38's... and while her "pothole" was more the size if a crater, she said she didn't see it until the last second and it knocked it out of time... if it bull scat, then it's on the person that told me about it. Take it easy on a guy :sheesh:

- Justin <><