Melted fuel pump relay L67 (Page 1/1)
dnthmn87 MAR 25, 01:16 PM
Hey guys, I got the frankenfiero running after replacing the timing chain and sprockets. It has the 3800 supercharged swap. It was running good enough to register and drive to work. But on the second day of going to work it wouldn't start because the fuel pump wasn't running. Swapped out the fuel pump relay and it fired up, although I could tell it had been hot, the plastic insulation around the end of the wire was dark and brittle. I only made it about 15 miles and it stopped running, popped the hood and the new fuel pump relay was MELTED!! I bought this fiero with a nonrunning fuel pump. Previous owner had upgraded the fuel pump to be able to run E85 eventually. Still running 91 octane. He only made it about 15 miles after replacing the fuel pump, it died and he sold it to me. So
when I bought it, I dropped the tank and had to clean corroded fuel connections to get the pump to work, but even back then I noticed one of the wires to the fuel pump relay had been hot. So is this new fuel possibly bad? Or just needs more than a 30amp relay? Id rather not drop the tank again and put the old pump back in it, but that one worked for 6000 miles without these issues.
fieroguru MAR 25, 03:12 PM
It is getting hot for a reason... too much resistance in the wires, poor electrical connections, pump drawing too many amps (high flow pump), fuel pump fuse replaced with one that is larger than stock, etc.

Spoon MAR 25, 06:51 PM
Frankenfiero L67..............Find the manufacturer's specs on your fuel pump & look for amps xx.
Then make sure your using the correct rated fuse based on the max amps..
Check the fuel pump wiring circuit to be sure your using the correct gauge wire.
Check the running amps of the fuel pump.
Check for clogged fuel filter, that will increase amps and possibly blow a fuse if its really clogged or in your case the wire IS THE FUSE and it will melt.
Make sure no other loads are on the same circuit as the fuel pump.

Or just read this link and run a new circuit.

http://www.gmtuners.com/fiero/hot_wire.htm

Spoon

------------------
"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut