Fuel Problem

[01mudslinger]

I have a '88 Gmc Jimmy, 350 with Throttle Body, I have never had this thing spit or sputter at all no matter how steep or angle of the hill it has been on, the other nite we were four wheeling i got it on a hill and it started bogging and sputtering and cut off like it run out of fuel and would not crank we got it back on flat ground and it fired right up. Tried a couple more hills and the same thing, I changed the fuel filter and that did not help. Is it the fuel pump ya think?

 

[Bent77]

Could it be that when pointed uphill, you uncovered the fuel pickup? I am not familiar with the intank pumps, but make sure you don't have any line blockages or anything in the tank obstructing the pickup.

 

[01mudslinger]

yea thats a possibility too, i was kinda goin off the logic that gravity was helping the pump on level ground and on a hill the pump has to push the fuel up to the motor and maybe it wasnt strong enough to do so now. Is there anyway to check the pump to see if its good before i buy another and take that one out?

 

[vortec]

do a fuel pressure check. i'm going to do the same thing with one of my trucks soon for a different problem.

gravity should not affect a healthy tbi fuel system except for exposing the pickup to air, as was already mentioned. a full tank of gas prevents that problem. if you got air into the sustem, that would explain why it was reluctant to start up once you were on flat ground.

don't forget that low pressure could be the regulator. much easier to replace than the pump.

 

[dyeager535]

It very well could be that the sump (/baffle) is broken in your tank. Except for a prolonged hill climb with a very low tank, you shouldn't run dry.

 

[trikstark5]

I just had a similiar problem except it happened every time I drove. When sitting idle, it ran fine, but once in gear and attempting to drive it, it just spit and sputtered. It ended up being my fuel pump. I changed the fuel pump, the filter on the bottom of the pump and the fuel filter. Problem gone.