1995 Jeep Cherokee is a Bucking Bronco

You need to clarify what you mean by fuel levels are low. That could mean sucking fumes.

If it climbs the hill when the tank is full then I would look no farther than the fuel pump. Had one my self that when the vehicle head up grade in the mountains would only go so far then die out. Got it back down in the flat started right up ran fine tried again. Made few feet farther then the first time before it died. The pump just could not handle the head pressure when the fuel line was up grade. That was even with a full tank.

You may be experiencing the same thing in symptoms of a pump going bad.

"You need to clarify what you mean by fuel levels are low. That could mean sucking fumes."

I would agree with ozzb here: define "fuel levels are low".

Being the pragmatic guy that I am, if keeping the tank, say, above half full, you don't get the problem, then, by all means, keep the tank at least half full.

You need to clarify what you mean by fuel levels are low

This is a tough one... the fuel level at which the problem occurs seems to vary in proportion to the demand placed on the engine... if I'm driving with no load I would say the problem occurs when I am below about two gallons remaining in the tank, however on a recent trip into the canyons with a 3500lb ski boat I encountered this problem with almost half a tank of gas (~10gal) on an incline of about 6% (if memory serves)

I should also mention that I first encountered this problem more than 3 years ago, I had the tranny flushed and the problem seemed to go away until about a year ago when I ran out of gas and it started happening again. It is very intermittent and aside from my return trip from the lake it has not occured with enough regularity for me to really get a feel for it.

Running out of gas is the thing that is hardest on an electric fuel pump. do it once and the pump could be trash from then on.

GA for that.

I completely forgot that point!!

Why thank you Andy, it's something a lot of people forget or don't even know. I myself have to constantly remind my boys to not let their tanks get to low for just that reason.

After replacing 3 fuel pumps this year (one on each of their cars) I think they have the picture now LOL

Cheap test: Try a can of "dry gas". When the level is low you will get intermittent spurts of water through the fuel line, if there is any in the tank. Run the tank damn near dry, then fill up, pour it in, and run it almost dry again.

Would the people who tagged this comment as off topic please clue me in??? It's in response to my post and I think it is a good answer... a bit more technical then I was hoping for (mainly because I don't have an oscilloscope) but to me it sounds right on the money.

He might have given himself "Off Topic" (5 points)and received 2 "On Topics" which have taken his 5 back down to 3!!

strangely that seems to make sense... of course I was just reading an explanation of english currency so maybe my brain is confused...

Thanks for the insight

If you find water in the tank, add meths to a half full tank, about half a pint should usually do it....it will carry the water with it through the engine.

Also, check if the fuel filter is dirty or has trapped water in it.

Find out if you have 1 or 2 fuel pumps, some cars have 2 and when one goes out, the other cannot cope under all conditions.

Have the fuel pump checked for pressure.

Have the tank checked for rusting (if not plastic) and rust lying inside on the bottom of the tank. this happens when you let the car go for long periods with little fuel in it, or oonly put a couple of gallons in each time. Always filling a tank full is a great idea......if its steel.....

I have seen the rubber connector between the fuel pump and sending unit get a hole in it and cause a similar problem, when the fuel level gets below the hole it sucks air in.

any thoughts on investigating this theory without dropping the tank? Frankly if I get the tank dropped I'm gonna replace the pump whether it needs it or not... with my luck it'd crap out the day after I put it back together anyway... Thanks for the input, I'll be sure to check for this when I do eventually wind up replacing the pump.

Gas cap? Cheap check...

not the gas cap, good check though, never can tell with these engineering types... they might remember to tie there shoes but never put them on...

thanks for the great response, this gives me much greater confidence that I'm going to be replacing a fuel pump not a transmission...

Try manual downshifting. If the problem goes away, transfer case problems and front axle driveshaft issues abound. I have found Jeep fuel guages lie about how much fuel is in the tank. Just keep the tank filled (1/2+) and you may never have another problem. Besides, the full tank prevents condensation and frozen fuel lines. Use a product called "Sea Foam" to remove water from the tank. I really suspect that is the real culprit.

Ray Cockrell

Warren Wilson College Autoshop

Agreed completely if fuel pressure is correct.

I agree with you as well, I had forgotten about sea foam great stuff!

I have tried downshifting, and if anything I would say it got worse.

My gauge has been pretty accurate so far, at least full is full and empty is empty...

I will definitely try the sea foam, though I can say with confidence that frozen fuel lines are not likely to be in my immediate future... I think we've had our 2 days of freezing overnight temperatures and any day now the 'snowbirds' will come flocking back to clog up our freeways and plow under our beautiful desert...

There may also be another, partially blocked, filter in the tank itself, more of a "Strainer" than a filter really.......