Bronco ll 1986, roughs great with full tank, very rough with low level in tank
Asked by kenmay Nov 15, 2013 at 03:19 PM about the 1986 Ford Bronco XLT 4WD
Question type: Maintenance & Repair
1986 Bronco ll, 2.9L fuel injected., new plugs, dist cap, fuel filter. Cleaned fuel injectors
and tested fuel line pressure.
Climbs hills no problem with a full fuel tank. Half full, seems like there is a governer at
3000 revs, oscillates between 3K and 2.8 K. At a quarter full, seems to almost die, revs
up, drops revs. No acceleration, only on hills. My mechanic is at a loss.
4 Answers
Have you pulled the pump/sender out of the tank to check the fuel pick-up? It's just a light-weight nylon sock on the end of the pump.
No, we checked the fuel pump pressure, but obviously not on a hill. I will get my mechanic to do that. We did have a new fuel gauge so years ago, not sure if that was the start of the problem as I normally keep the tank full.
I remembered the late '80's - Taurus fuel tanks would "oil-can" on a warm day - the bottom of the tank would pooch out and drop the fuel below the pickup tube. They'd run out of gas with a 1/4 tank of fuel on the gauge.
That's is the same in my Bronco, I was thinking that the new fuel gauge is set wrong because it seems out of gas at 1/4 full.
