My car is a 600whp stock 125,000 miles block running a walbro 450 e85 pump. The pump is wired correctely with the science of speed wiring kit and the walbro 450 install kit. My setup has been trouble free for years but today all of I sudden when cruzing the car will buck because the airfuel would go to full lean. I have a air fuel gauge. The car would do this non stop. But I limped the car back home and I found that the fuse holder for my fuel pump is badly melted. I checked the wiring and it all looked fine and the relay for the fuel pump looked fine. I replaced the radio shack fuse holder with the fuse holder that comes is the SOS fuel pump wire kit and the car still does the same thing. Just cruzing and it will buck and go full lean. What the hell happened? The new fuse holder is fine and is not mealting. So I don't know what to do now? I will try to pull the fuel pump hanger out tomorrow and have a look. But I don't really know what wrong. Do you think the fuel pump shorted out ?

 

Fuse is designed to blow, not melt the fuse holder. Is the holder shorted? How many amps should the pump draw?

-- Chuck

 

I've seen a fuse holder melt when the fuse didn't have a good connection to the gift fuse (thank you Swype ), creating a high resistance point which can generate a lot of heat. I don't think the pump shorted, or the fuse would have simply blown.

None of this explains what is happening with the car overall though, unless the pump was damaged by being starved for voltage by the high r in the fuse holder. I can't say if that is very likely or not though.

 

How's the relay looking after all this?

 

the relay looks fine and is not mealted at all.

 

This is what mine looked like
Is your in tank hose designed for E85?

 

I usually see signs of melting when something pulls too much current for what it was designed for. Looks like the radio shack fuse holder is rated for 30A (probably peak, not continuous), and may not be able to handle the quiescent high current pull of the pump (just a theory). After you get everything up and running, touch the fuse holder and see if it gets hot after running the car for a while. May need a better quality fuse holder (I use the marine grade stuff myself).

 

I have used this radio shack fuse holder to power my fuel pump for at least 4 years at over 40,000 miles with no issues. Also I just swapped out this melted radio shack fuse holder for a fuse holder that comes in the science of speed fuel pump rewire kit and the car still had the same issue!!!! There has got to be a short somewhere or maybe the fuel pump went bad? I don't know but I need to pull the pump I supose.

 

This...

The radio shack stuff has gone down in quality. It seems that pump pulls up to 25 amps. Make sure all connections and terminals are tight. The reason its melting is that its too high of a resistance on that wire.

This could happen many ways. The return line is getting kinked thus turning up the load on pump, bad FPR will also do this. Id also check any and every connection that is soldered. Butt connectors sometimes corrode and cause more resistance on the wire. With an ohm meter you can test the main wire. Last thing it could just be the pump on its way out creating a load close to 25amp or just under. it. good luck