fuel/electrical problems

[area51js1]

starved for fuel (update)

I have a 1986 Bronco II 2.9L 4WD. It ran fine, then started getting rough and cutting out and finally it won't start anymore. I can get it to turn over with starting fluid but when the prime runs out, it dies and there is no gas smell to the exhaust. The fuel pump relay clicks and the high pressure fuel pump under the driver side kicks in when I turn the key on, but both the pump and relays are erratic. What I mean is that the relay clicks on and off intermittently (rapidly) and the fuel pump follows. However, sometimes the fuel pump runs when i turn the key on but then it doesn't cut off as it should.

I checked the fuel pressure and it is not pressuring up. When the pump kicks in and doesn't cut off, the pressure reaches ~16psi but no more. If I turn the key off, the pressure doesn't fall but when I release the pressure from the tester, there is no gas bleeding off. If I just turn the key on and gently depress the schraeder valve on the fuel rail, I first get air followed by a little frothy gas.

Does this sound like a high pressure fuel pump problem...I replaced it about a year ago so I would be surprised that it would go out so soon and it does turn on. Would the low pressure pump in the gas tank cause these symptoms? I tried listening at the gas tank and I don't hear anything but the noise of the high pressure pump could be masking it and I don't hear as well as I used to.

 

[southernlifttruck41]

Low pressure pump in tank. FUN.....

 

[area51js1]

Just to follow-up...I checked for power to the in tank low pressure fuel pump and it registered ~11.8V so I was good there. I pulled the reservoir from the fuel filter and briefly turned the key on...no gas. I replaced the low pressure fuel pump in the tank and she's running fine. And yes, even though it's only 4 bolts to remove the skid plate and 2 bolts for the straps on the gas tank, it's a real pain to drop a fuel tank.

 

[Hardwareman]

I'm having a fuel problem myself right now. I'm glad you've got yours fixed.




Allen

 

[djurs]

Fuel pump is easier to get to by disconnecting the plugs going to the tail lights and taking bolts to gas filler out, 6 bolts in the bed, and take the bed off. Easy easy if you have someone to help you lift the bed (which is really light but awkward)

 

[AZ86B2]

Fuel pump is easier to get to by disconnecting the plugs going to the tail lights and taking bolts to gas filler out, 6 bolts in the bed, and take the bed off. Easy easy if you have someone to help you lift the bed (which is really light but awkward)

I would love to learn that trick, since my B2 just started doing the same thing as his.

 

[grnrngr]

Kinda hard to lift the bed off a B2..

 

[gbadgley]

It's easy, but instead of bolts, just use a torch!! Sorry about the paint.

 

[grnrngr]

Heh...I really wanna do that to my B2....chop the top and make a canvas cover for it...

 

[djurs]

Just looking through old threads... Didn't see it was a B2.. But you're all very funny.