Thread: Fuel starvation on steep incline

Yep i had the same problem with our Isuzu rangy. The long range tank pick up would suck air on steep up hill runs with low fuel. I then made up a 4lt swirl tank that the motor runs off and it has a constant flow from the main via a facet fuel pump.Of course it has a return as well. Never had a problem again.

justin

The strange thing is it is a standard tank and it was 3/4 full. I would have thought the fuel pickup would have been designed to handle such angles. Looks like I might have to drop the tank and have a look at what's going on.

I had the same on a Toyota 3liter b diesel , it was the lift pump which is part of the injector pump, probably the same on the isuzu if its a nippon denso pump, actually it only happened on hills that were almost too steep for a Toyota so I didn't worry about fixing it and bought a Landrover instead.

It might be the primer filter. Does it do this on long steep highway hauls too ?

There is a tiny gauze filter in the fuel line basically under the primer, it can clog up & give the impression of fuel starvation. Its about the dia of a pencil ( smaller than 5cents) and difficult to access as its near the engine mount.

Only happens on steep low range type inclines. I have only recently checked that small gauss strainer under the lift pump (clean as a whistle) and have also recently changed the primary filter. Maybe I should strip the water trap filter near the tank - not sure if that could have anything to do with it.
Is it very hard to drop the fuel tank, ie impossible to get at bolts, usual LR style

It sounds like a problem of suction lift vacuum, perhaps the lift pump is dying or its inlet pipe is leaking faint traces of air. I would try using a switched Facet pump at the tank end of the fuel line, simple fix and aids priming.

If you park it nose downhill does it leak any fuel?
Could be an air leak that only really shows up when the tank is much lower than the lift pump so the lift pump is having to suck harder.
Pointing it downhill might show a leak in the area if thats the case.

Steve