Hi everyone
I have a problem with my 88 yj. My jeep has a 4.2 engine and I have a motorcraft 2150 on it. The jeep has the nutter bypass as well. TIming is set at 10 degrees btdc spark plugs are good.

My jeep starts fine and idles smooth but I have found that when it starts to get under load ie going up a hill it will buck and hesitate. If i let off the gas the bucking stops. Also if I put the clutch in and rev it sometimes that helps too. I have checked the acc pump on the carb and it seems to be working fine. I checked the vacuum and it holds steady at 21 while at idle. My jeep never had this problem before. I checked the fuel filters and they are both fine. My pcv valve needs replacement and my air filter should be changed but I wouldn't think this would cause this problem.Oh and i disconnected my egr but no difference I also cracked my gas cap and still no help. When it dies it usually needs to be pumped in order to start or it just turns over for a while then starts.

My question is would this be a simple as a blown power valve or low float level or might it be a fuel pump or screen issue. I really would prefer not to drop the tank if i dont have to
Oh yeah I tested the fuel pump and it was pumping at 5-6 psi.

ps forgot to mention that my jeep will lose power just cruising again seems to go away if i take my foot off the gas for a sec then ease back into it.

Appreciate any and all help.

 

The fuel preasure sounds ok but it sounds like its starving for fuel at higher speeds so try a new fuel filter. I have hade mine do the same thing.

 

I had the exact same Jeep with the exact same problem. I can't remember for sure how I solved the problem but for some reason I think it had to do with the dumb throttle body carb they put in those things. Maybe try looking into that?

 

do you have a converter on it. It may be plugged.