Question-------------------------
Van, I found no fuse on the firewall by the relay.The only fuse is a fusable link that goes into a block mounted on the firewall up on the right facing the engine.It has power on both sides of the link. The only thing that resembled a clip was a connector but there was no fuse,and it went to the a/c compressor.This thing is driving me nuts. When the trouble started, the truck cranked that morning but wouldnot crank that night and hasn't since. I've even changed the ignition in the steering column.
AnswerHello Allen,
That surprises me.
First, I would expect an 87 to have a mechanical fuel pump, and a carburetor. But that is about when throttle body was starting, so I bet you are correct on that.
The earliest TBI fuel systems I remember had a plastic cover on the firewall, passengers side. Three big plastic nuts hold it in place.
Under the cover is the fuel pump relay, a junction block with about six studs, and a little plastic wire connector clipped to the firewall.
Inside that connector, when popped loose, is an inline fuse for the fuel pump.
When the key is turned to run, that fuse becomes energized, and the pump in the tank runs for about three seconds.
I really don't know if there was an earlier version of injection that had the fuse somewhere else.
Another thing that would keep the pump from running is a bad ground at the frame near the tank.
And one other thing I found in a truck not quite that old, was the wires inside the top of the tank unit. There are rivets through the top of the unit that carry the power in, and to the pump. The rivets were rusty and loose.
If you have dual tanks, and a switch on the dash, make sure it isn't stuck in the center position.
Van
