Today I had to make a 200 mile trip home. My average speed was approximately 70mph the whole way on the highway. When I had about a quarter tank of fuel left the Jeep started acting funny. It would all of a sudden lose power for a split second and then regain speed like nothing happened. This went on for about 10 miles before I could get off the highway and pull in a gas station. When I filled up it took 8.5 gallons so I know I had plenty of gas. Last weekend I installed a Kilby skid and replaced the fuel sending unit. Here is what I think it could be, a bad gas cap or I screwed up something when I pulled the fuel pump out(but I don't know what that could be). The only problem is it has happened several times before, but those times produced error codes leading me to believe I had a bad O2 sensor, which I replaced in the exhaust manifold. The strange thing is that it doesn't act like this when I am running around town and below a quarter tank. Any other ideas/opinions?
TIA
Vehicle Specs: 97 TJ 2.5L manual 103k miles if it helps

You replaced your sender.... does it go all the way to the bottom of the tank???


Oh, and loose the JU .sig

And welcome! :flipoff2:

Yeah it should go to the bottom, plus I have a 15 gallon tank, so plenty of gas left over

did you disconnect the battery before doing this work?.....also you may want to replace the fuel filter that sits on the frame rail by the tank.

there are no filters on the frame rail.. they are on the sender.. Fawkin DC

my friends YJ had one in the tank and on the frame rail...did the work two weeks ago

my 4.0L chero does something similiar but it does it at random whether it has a full tank or half, it doesnt matter. And it turns the engine totally off for about 2-3 seconds then all of a sudden fires right back up and keeps going like nothing happened. Anybody what this could be???? :D

Water in the gas. Try putting some gas dryer ( Rubbing alcohol works ), in the tank, and it wouldn't hurt to change the fuel filter as stated above.

Originally posted by CJ3BWILLYS
Water in the gas. Try putting some gas dryer ( Rubbing alcohol works ), in the tank, and it wouldn't hurt to change the fuel filter as stated above.

Water in the gas? Are you refering to mine or his post? Sorry for sneaking this question in I should have started a new post.

Mine seemed to have the same problem Rockbuggy was having with his. Disconnecting teh battery was the first thing I did. After I was done I got some dry gas and put it in just in case I got any water in the tank since I rinsed some of the dirt off. Since I have 103k miles on it the fuel filter could need replacing as well. Thanks for the ideas

I'll try that. mine has about 99,000 mile on the same fuel filter too. I guess its worth a try im sure it needs one anyways. I just hate puting any money in my daily driver :( Id rather buy something for my Rockbuggy :D

It may sound funny, but I've known a couple of people to have this problem, and it didn't relate to the fuel system at all. When's the last time you changed the distributor cap? It is possible that one or more of the connections is missing, causing a misfired plug, and possible stalling sequence.

I have about 5k miles on the distributor cap, in fact I had it off the other day and the terminals were clean. If there was a problem with the cap wouldn't it be noticable no matter how much gas I have in the tank?

Originally posted by Rockbuggy


Water in the gas? Are you refering to mine or his post? Sorry for sneaking this question in I should have started a new post.

The original post :)

You would think that a distributor problem would be noticable at any speed and/or level of gas. But at only 5000 miles on it (and presumably the wires as well), I wouldn't expect the cap to be the problem. A visual inspection probably wouldn't tell you much, because my old and new looked nearly identical, but the new one worked.

My problem started out only occuring on the highway at high speeds, so I thought my engine was choking itself with lack of fuel. We tested the fuel line pressure and it was fine. You might try testing the fuel line pressure. The stalls which would usually self-recover (ie stall, then start back up with a heavy dose of gas, before actually stopping entirely). Eventually the symptoms got worse and it was stalling completely and the only way to start it up was to ground a spark plug on the engine.

Good luck.

I had this same exact problem with mine. It turned out to be the fuel filter. I had put in a new sending unit with a filter on it, but I guess the filter on the sending unit isn't as tight as an inline-filter. I had tons of gunk in the tank from having it out of the truck for so long empty. But it only happened on the highway because that's the only time I would have it running long enough to gain up enough gunk in the inline filter to clog it. I would pull over and bang on things in the engine compartment and it would seem to work for a few more miles and then clog up again. I didn't know why until I replaced the filter just in case and it worked great. What was happening is, every time I banged on stuff in there, I would knock the gunk out of the filter but it would just rest on the bottom of the filter housing. Then when I drove again it would suck it all back up. I put a see-thorugh filter on the first time I replaced it to see what was happening and after about 3 filter changes I had finally gotten most of the gunk out of the tank and I no longer have to change filters. I checked my float bowl and there was almost no dirt in it, so I guess the filter was doing its job.

J. J.

MY yj has been doing the same thing, I'll try the fuel filter.

If this does turn out to be ya'll's problems, make sure to check your float bowls. If your filter wasn't good or if it was worn, you may have dirt in the bottom getting sucked thorugh your carb, which is not good.

J. J.