Failed Walbro Pump

[saleen07gt]

I'm looking for some advice on a fuel pump. The car is an 07 with a 2012 Coyote motor, bolt-ons. Anyway, I modified the sender for a fuel return, installed a 255 lph Walbro pump (GS342 I believe), the fuel pump driver module has been bypassed so the pump runs at 100%. It has run for about 3 months and yesterday it crapped out. Is the pump too small for the application or is something else causing it fail prematurely?

 

[JeremyH]

How is the wiring to the pump setup? That's the most often overlooked thing and if not done right can cause increased current draw and heat, loss of pump flow as well and increased pump wear. That and their are a lot of poor quality knock off walbro gss pumps on the market today, so is the source of the pump reliable? I would also say it may be too small flow wise for the motor depending on how you have it setup. FYI the oem coyote pump flows around 350lph. How are the lines, regulator, rails and return setup?

 

[saleen07gt]

How is the wiring to the pump setup? That's the most often overlooked thing and if not done right can cause increased current draw and heat, loss of pump flow as well and increased pump wear. That and their are a lot of poor quality knock off walbro gss pumps on the market today, so is the source of the pump reliable? I would also say it may be too small flow wise for the motor depending on how you have it setup. FYI the oem coyote pump flows around 350lph. How are the lines, regulator, rails and return setup?

As far as the wiring goes, I looped the power and ground wires at the fuel pump driver, didn't seem to be getting hot but fuel pump continuously runs with key on. I had a return welded into the top of the 07 sender right above tbe pump. The fuel filter is Corvette style with built in regulator. The problem might be with the source of it actually being an authentic Walbro pump, it said it on the box, I purchased it off Ebay for around $50-60. I've tried to contact the seller but he hasn't responded. I had no idea the factory Coyote pump flowed that much. I have access to a very low mileage Coyote pump, I'm wondering if I can remove it from the sender and use it in my sender. The sender doesn't look like a direct drop in, they look a little different. What do you think ?

 

[JeremyH]

So couple things, oem 16awg wiring from the inertia switch to the fpdm wasn't really ment to handle an always on pump load. You will want to use the oem power wire coming into the fpdm and run it to ground through a relay as a trigger and then feed the fuel pump directly from the battery through the relay to the fuel hat plug. Then run the ground wire for the pump at the fuel hat plug to chassis ground, there are a few bolts close by right under the seat to do so. I would use at least 12awg, 10awg if you like. That's an interesting route you took with the filter regulator do you monitor pressure?

Yeah there are fake $10 pumps from overseas all over ebay. I would stick to an authorized walbro distributor.

Yes you can modify the 3v fuel hat to fit the coyote pump I have never done it but it has similar dimensions to a dcss 39/50 walbro pump which I do install on the 3v fuel hats.

 

[saleen07gt]

Thanks, that is good info using a relay that way. I do have a Coyote fuel pump driver and pigtail I can wire in. The Vette fuel filter is supposed to maintain 58 psi, it was simple and cheap vs. buying a regulator, fittings and running lines. I have not monitored fuel pressure yet. When I turbocharge this thing I will get more elaborate with the fuel system, for now it just has to be reliable as I save for a bottom end.

 

[JeremyH]

Yeah they actually restrict to a similar pressure range as what coyote runs from factory, so found it interesting, cool idea for a basic setup. You wont need any driver module for this setup just a key on power source to trigger the relay (factory inertia wire is the best choice) power supply and chassis ground for the pump. I have built a few wire kits for a return setup of this nature. I have a diagram and directions on how to do it that I can email you this evening when I get home.

 

[saleen07gt]

Yeah they actually restrict to a similar pressure range as what coyote runs from factory, so found it interesting, cool idea for a basic setup. You wont need any driver module for this setup just a key on power source to trigger the relay (factory inertia wire is the best choice) power supply and chassis ground for the pump. I have built a few wire kits for a return setup of this nature. I have a diagram and directions on how to do it that I can email you this evening when I get home.

Awesome!