Really hot power and ground wire

[Chad1993]

To start off I have a 3 month old Walbro 255hp fuel pump rewired. I used the kit from STM. My fuel pump has always been quiet. No back seats either. Just recently I started to notice it getting louder, and when I try too boost I'm leaning out before I reach 10psi when the goal is my regular 20psi. I took the cover off of the pump and noticed that my electrical tape has melted onto the hot wire and the ground wire. I also noticed that the connector that the relay goes into has bubbled up from the heat. I got the old tape off and cleaned the connections and tested the volts, I'm reading in the high 13's in voltage. And high 12's when "trying" too boost. I went ahead and retaped all the connections. The wires get so hot it is unbearable to touch just for a moment. It looked like I had a leak at the afpr, so I took the gauge off and Teflon taped all the threads. No noticeable leaks now. Brand new diaphragm, like a month old. I've read through the forums and didn't find much. Only that maybe my ground is bad, but both ground and the hot wires are really really hot. Any ideas? Thanks.

 

[Blurred Talon]

Sounds to me like the wire is not a suitable gauge for the current flowing though it. A wire that is not of a thick enough gauge for the current it is passing will heat up and possibly melt, this can in turn cause a fire.
I highly recommend going back to the stock wiring configuration until you figure this out.

What gauge is it? Do you have an inline fuse on the power?

 

[Chad1993]

Not sure on the gauge, just whatever STM sells in their package. I do have an inline fuse. The wire itself is normal temp until it connects to the smaller wire to the pump.

 

[NordicSaab]

The other thing it could be is the fuel pump is internally shorting.

Maybe pull the fuel pump and see what type of resistance you are getting through the sytem. If the Ohms are too low it may be a faulty pump pulling too much power.

As others have said this is a serious issue, please investigate further before driving the car regularly.

 

[Chad1993]

I changed the fuel filter just 30 minutes ago but didn't change anything. I've read that walbros get loud during warm/hot days but this is extremely loud. It starts out quiet like it usually ran at 15-20psi then it progressively gets louder. You wouldn't happen to know what the resistance should be?

I don't think it's suppose to look black right there.

With ohms set to 200 I got .07 resistance.

.7 rather. Connected to the positive and negative prongs that the connector connects too.

What is that black gunk where the fuel pump goes? The pump is also pulsing when I turn it on via laptop. If I turn the pressure down to say 30psi at the regulator it whines constantly, the way it's suppose to be. So 43.5psi of fuel pressure is straining the pump. I redid the wiring for the rewire and I'm getting 13.8 when running and driving. So do y'all think that black crap ruined the pump or do you think I can lube up the pump, drop the tank and clean it, then put some nice 93 octane with no ethanol and make a difference. Or should I go ahead and order another pump? It's the only thing I know to do next.

Anybody?

 

[Blurred Talon]

Could be dirt in the tank causing the pump to work harder, this would in turn cause the pump to draw more amperage.

 

[NordicSaab]

Sounds like your pump is toast.

Generally a fuel pump should be around 40 ohms resistance. .7 is almost an open ground fault.

 

[Chad1993]

I'm guessing whatever that black gunk is made my pump clog up some, and made it over heat itself. I'm ordering a new one ASAP.

 

[Chad1993]

Got the tank cleaned out, and new pump came in yesterday. I'll let you guys know what happens.

 

[shakeandbake]

From working in the field I found that ohm tests don't really mean much cause the motor is not in its natural state. Voltage drop tests and amperage tests have been a much better diag tool for this kinda thing.

 

[Chad1993]

We will find out soon enough.

Fuel pressure is stronger than ever, 43.5 base fuel pressure and no needle movement at all with vacuum line off. Boosting at a 10.0 to --- on the AEM UGEO. I know that's rich but it's better than over 16.0 to --- . So to conclude this issue. The pump filter got so clogged up from the O ring for the pump assembly falling into the tank and turning into a kind of powder thus making my pump run harder and hotter in turn making the wires really really hot. Thanks for all the input and advice! SOLVED!