Have you had this problem, If so, What was the fix?

[R***A**N**G**E***R]

My truck starts right up and runs perfectly on FLAT roads but just as soon as I come to the base of a hill and start to go up the hill the truck starts jerking violently but just as soon as I crest the hill and I am on FLAT road again it stops.

I drove 10 miles today to town on FLAT highway at 65 miles an hour but just as soon as I got to the couple of hills and started going up them it started jerking like crazy and stopped just as soon as I was off the hill.

What in the hell could be doing this??

 

[Heavyfire14]

dirty MAS or o2 sensor?

 

[Captain Ledd]

Mine was doing something similar, the timing had jumped. Mine did it whenever I gave it throttle past 60/65 MPH. CEL also started flashing. I would equate it to the engine trying to escape from under the hood.

 

[R***A**N**G**E***R]

Mine was doing something similar, the timing had jumped. Mine did it whenever I gave it throttle past 60/65 MPH. CEL also started flashing. I would equate it to the engine trying to escape from under the hood.

Mine is not throwing ANY codes.

 

[Bennybooster]

mebbe you are at a really low rpm and bogging the engine out

 

[tbirdsps]

Actually he's having a "duel stream" problem. Once it's back to a single stream it'll all be OK.

Really though it would almost have to be a fuel problem.

 

[kevinsranger]

maybe there's a check valve in the fuel pump like the chevy's have to prevent the fuel pressure line from back flowing back into the tank and dropping fuel pressure?

 

[triumphrider-1]

Maybe you are at a really low rpm and bogging the engine out

Really though it would almost have to be a fuel problem.

These were my thoughts as well. The engine load was to high for the given RPM and it started bucking, or the fuel isn't being picked up in the tank (whether from low fuel, pump, or pickup tube, or some variant).

 

[R***A**N**G**E***R]

Actually he's having a "duel stream" problem. Once it's back to a single stream it'll all be OK.

Really though it would almost have to be a fuel problem.

ha

 

[R***A**N**G**E***R]

These were my thoughts as well. The engine load was to high for the given RPM and it started bucking, or the fuel isn't being picked up in the tank (whether from low fuel, pump, or pickup tube, or some variant).

Can a fuel pump have an intermittent issue? or do they generally work or don't work?

Is there a way to verify that my fuel pump is operating at 100%, some kind of test?

 

[noahkenny]

My dads 4.0 suffered a similar problem. Turned out to be a vacuum line off at the throttle body. Check your vacuum connections around the mass air flow and your throttle body. It would run fine until you hit a hill or if you let your foot off the gas while gearing down.

 

[rockin86ranger]

I had a simialr problem in my 88 but it would very rarely act up on flat ground to, it turned out that the inertia switch was shorting out it just got really bad on hills

 

[Captain Ledd]

Mine is not throwing ANY codes.

The only code mine was throwing was a cyl #2 misfire. Other than that it was happy as a clam.

 

[RangerBoy94]

Mine does that but thats because I need to get it timed it has a little miss.

 

[R***A**N**G**E***R]

Update

So today for shits and giggles I called several auto places and told them exactly what my truck was doing and how it was 99.9% of the time doing it on HILLS and running perfect the rest of the time and everybody said if they had to GUESS they would say I need a new fuel pump.

What can I expect to pay to have my fuel pump replaced and if I take it to a auto place to have it professionally diagnosed and then have the same place do the work should they waive the diagnostic fee?

Also what do you think is a fair price if I buy the new fuel pump and have a local yocal/friend/knows everything about cars and how to work on them person do it at my house.

What say you what say all.

THANKS!!!!