Starting Problem

[M1llionb]

My 86 Bronco has been sitting for a while. It used to run... now it doesn’t. In the past I had issues with fuel system. Recently, I’ve replaced fuel relay, battery, and fuel filter. In efforts of getting it started. One odd thing is, I can hear the fuel pump running.... even though I don’t have the key in the ignition (this caused my battery to die...) In the past we brought the fuel tank down and replace the fuel pump inside and the fuel reservoir. My question is... how many fuel pumps does my bronco have? Is there one on the chassis and the other inside the fuel tank? Is the noise (even if key is not in the ignition) coming from fuel pump on the chassis?

 

[Tiha]

That looks like a 2 pump system.

The in tank pump feeds the high pressure pump on the frame rail.

Neither should be running with the key off.

Both should run with the key on, at least run for a few seconds before shutting off again.

Do you have a fuel pressure gauge? If you can verify pressure at the engine that will help narrow down or eliminate a fuel system problem.

Electric fuel pumps don't like sitting. The fuel evaporates and they tend to stick. Get gummed up.

 

[johnnyreb]

My 86 Bronco has been sitting for a while. It used to run... now it doesn’t. In the past I had issues with fuel system. Recently, I’ve replaced fuel relay, battery, and fuel filter. In efforts of getting it started. One odd thing is, I can hear the fuel pump running.... even though I don’t have the key in the ignition (this caused my battery to die...) In the past we brought the fuel tank down and replace the fuel pump inside and the fuel reservoir. My question is... how many fuel pumps does my bronco have? Is there one on the chassis and the other inside the fuel tank? Is the noise (even if key is not in the ignition) coming from fuel pump on the chassis?

Is it a AIRTEX PUMP? I went through 5 of them--ALL BAD. Finally went to Carter and fix the problem. If the pump is making noise WITHOUT the key on. Sounds like you have a short and should be checked. Since it drained you battery. Good luck.