I have a 88 Bronco 5.0 160k original miles. The truck would start then die right away then you would have to turn the key almost to the on position until you heard the high pressure pump prime again. Bought a new pump from napa seemed to work just fine for one day. Today turn it on died and i'm back to were I started. also now when the truck is one I hear a groaning sound come the engine compartment and also when I turn it off I dont run the AC because it doesnt work. Only thing I havent changed for the fuel system is the in tank fuel pump the regulator and the resvoir and or course the injectors. really stumped on this one so i need some advice. Also I'm looking for the relay or Power distribution box I cant seem to find mine I found only two relays and I know where my fuse box is but i cant find anymore relays, I know on like 90 or newer bronco theres the fuse box with the relays right by the airbox i'm looking for mine though, there just cant be two relays for the whole truck. so fill me in guys.

88 Bronco all stock.

 

 

Hey there, have a newer Bronco '91, but i will try to help; first thing is to make sure the alternator has power, reguardless if you have recently replaced it, it might be bad. Next, check the wires on the fuel pump, sauder them if necessary. (Mine is located inside tank) Last, i would recommend checking fuel filters for clogs of any kind. Hopefully this helps Check ignition system probs, distributor caps, rotors, etc.

 

I have an 86 and the fuel relay is below and to the right(looking at the front of the truck) of the master cylinder,mine had the same problem,and I replaced the relay

 

Yah come to find out it was the high pressure pump. everything else was fine though. I found the relay's by turning the key and listening to them kick over lol it worked took only a few tries though. thanks guys for your input though