So I wired in a secondary relay a long time ago when I switched to a Walbro GSS340 255 lph pump but it was pretty much all on the stock wiring. I have finally started the laundry list of things that need to be addressed on the Coupe and upgrading the wiring on the pump is at the top of the list being I am starting to push the pump with the 331 putting down a little over 460 fwhp. Tuner had to bump the base fuel pressure up to feed the motor in the 5,000+ rpm range and told me any more and it needed more pump. This caused me to go down a lot of rabbit holes doing research which lead me to a few YouTube videos.
I cam across this guy and what he was saying made sense:
I then found this video by Pro-M which sealed the deal as I could see what the guy above was talking about:
I am going to do the flexible fuel line extension on the stock hanger as I am still running the stock fuel lines. And speaking of the stock fuel lines I did some research there as Pro-M brings up the fact that the 1/4" return starts to become a restriction with a 255 lph pump. I do not see the pressure come up at idle on my car and I am running a full sweep Autometer electric gauge and it stays at 45 psig through a full pull in 4th on the dyno. I think with the short lines he was running and no engine consuming fuel is what contributed to that. I also noodled around and there are cars making 600+ fwhp on stock fuel lines so I am not messing with them. —-See Posts #8 & #12 as I changed my mind on this.—-
So to get this done I have ordered or bought locally the following:
(1) Fuel pump hanger lock ring and seal from AutoZone - Spectra Premium Fuel Tank Lock Ring, P/N LO03
(1) Fuel tank filler neck grommet from AutoZone - Spectra Premium Fuel Filler Neck Seal, P/N FNA03
(1) Fuel pump to hanger S hose from Walmart (quicker shipping) - Quantum P/N HFP-RH2
(1) Walbro GSS340 sock filter (strainer) from www.walbrofuelpumps.com - Walbro P/N 125-157
(1) Walbro GSS340 replacement electrical connector plug from Amazon - Ballenger Motorsports P/N CONN-76039 (fits 10-12 ga wire)
10 ga PTFE jacketed wire - Mar Vac Electronics (10' of black and 10' of orange)
(2) Rubber grommets 3/16" ID from Lowes - Lowes Item #423561
24" of 1/4" rubber fuel line from O'Reillys - Gates P/N 27002 (Gates website says good for all gasoline blends and E85) —-won’t be using this now, see Post #8 & #12—-
(1) 30A Bosch relay - I bought a lot of 30 a few years ago and still have some left so I’m going to replace the one I put in years ago.
New stuff due to going to a different hanger and upgrading the fuel lines:
(1) Pro-M fuel pump hanger with 3/8" fuel lines and 6AN fittings - Pro-M P/N HANG
(2) 25' lengths of 3/8" plastic fuel line from Amazon - Dorman P/N 800-072
(2) 5/8"(16mm) ID Heat Shielded Fire Thermo Armor Fire Sleeve Silicone Coated Fiberglass for Automotive Hose Lines & Electrical Wiring Black, 5 feet - BSTFLEX P/N FIRES16MM
(1) 3/8" ID Black Silicone Coated Fiberglass Heat Shielded Sleeve Fire Thermo Armor for Hose Lines & Electrical Wiring, 5 Feet from Amazon - KRD Performance M/N HSA-10-5_BK
(2) 6AN Male to 3/8" SAE Quick Disconnect Male Push On EFI Fitting Adapter Aluminum from Amazon - Evil Energy No P/N
(2) -6AN Female to 3/8 Male EFI Adapter from Amazon - Fragola P/N 491995
(1) Fuel Line Straight Quick Connector - Adapts 3/8 In. Steel To 3/8 In. Nylon Tubing from Amazon - Dorman P/N 800-082.5 (box of 5)
(1) Fuel Line 90 Degree Elbow Quick Connector - Adapts 3/8 In. Steel To 3/8 In. Nylon Tubing from Amazon - Dorman P/N 800-086 (single)
(1) 3/8" Fuel Filter (quick disconnect on both ends) - WIX P/N 33243, Good for 75 psig
(1) 3/8" Inch Stainless Steel Cable Clamp, Rubber Cushioned Insulated Clamp from Amazon - Lokman P/N LK-88 (20 Pack)
(1) 3/4" Inch Stainless Steel Cable Clamp, Rubber Cushioned Insulated Clamp from Amazon - Lokman P/N LK-88 (20 Pack)
So the plan is to remove the orange rubber nipple from the 1/4" return line on the fuel pump hanger and add about 12" of 1/4" rubber line to the hard line with a clamp. When the pump goes back into the tank I will use a long screw driver or whatever to guide the hose outside of the slosh baffle that the pump sits in. If it is a pain in the rear then it will go inside the baffle. —- See Post #8 and Post #12 as I changed my mind on this...twice—-
I watched a few videos of increasing the wire gauge size to the pump and this guy always cracks me up and he had a video on it. About the only thing I am using from his video is drilling the rivets on the factory white connector and running the wire through those holes. Watch the rest of the video at your own peril...
Most of the videos reused the wires on the hanger which I do not want to do. I am going to use his trick on drilling the rivets, enlarging the holes for 0.1875" ID grommets, and passing the 10 ga wire through them. If the wire is a tight fit through the grommets a little dish washing liquid may be in order. The PTFE jacket on the wire will be really slick so it may pass right through. Did a bit of reading on what to seal the grommet and wire to the hanger and the resounding answer was two-part epoxy. I plan on covering the entire grommet as they are just rubber and the gasoline will eat them up over time. I am only using them for chaffing on the wire so covering them top and bottom with the epoxy is not an issue. I am also going to cover the end of the crimp connectors that go into the fuel pump connector with the epoxy as I do not want fuel to migrate up the wire. This will get the pump installed into the tank and next will be getting the wires into the trunk.
I will be installing a Delphi Weatherpack connector so that I have a quick disconnect under the car to get the tank out. Just in case someone does not know what a Weatherpack connector looks like (finding a smaller image was taking too long):
I will use the 12V+ and ground in the stock wiring harness to trigger the 30A Bosch relay that will be mounted in the trunk. The relay will be mounted behind the panel that covers the rear tail lights and I will ground the pump at the same location. I will run a 10 gauge wire from the battery back to the relay and fuse it up by the battery with a 15 amp fuse and see if the inrush when the pump starts pops that or not. Most say that they have 10 amp fuses and have no issue but all the new wiring will support more than 15 amps so things should be safe.
The whole idea behind this is to keep the voltage as high and steady at the pump as possible. With the age of the wiring on the car, the factory power wire being 14 gauge, the power wire passes through five connectors. Power starts at an 18 gauge fusible link that is at the starter solenoid on the inner apron, goes to the fuel pump relay, then to a connector in the passenger kick panel, then to a connector in the driver kick panel, then the inertial switch connector, then the disconnect plug between the body harness and the tank harness under the car, then the connector on the fuel pump hanger, and then the fuel pump connector. After I rewire it there will be a fuse, relay connection, weatherpack connector, and then to the pump connector. My guess here is right now it is loosing over one volt based on all the connections and the length of the wire. The additional volt will basically net the flow rate about 35 lph at 45 psig.
Anyhow, I will update this as progress is made. Right now I have the tank out and the hanger stripped. Progress will depend on how busy the week is at work.
I cam across this guy and what he was saying made sense:
I then found this video by Pro-M which sealed the deal as I could see what the guy above was talking about:
I am going to do the flexible fuel line extension on the stock hanger as I am still running the stock fuel lines. And speaking of the stock fuel lines I did some research there as Pro-M brings up the fact that the 1/4" return starts to become a restriction with a 255 lph pump. I do not see the pressure come up at idle on my car and I am running a full sweep Autometer electric gauge and it stays at 45 psig through a full pull in 4th on the dyno. I think with the short lines he was running and no engine consuming fuel is what contributed to that. I also noodled around and there are cars making 600+ fwhp on stock fuel lines so I am not messing with them. —-See Posts #8 & #12 as I changed my mind on this.—-
So to get this done I have ordered or bought locally the following:
(1) Fuel pump hanger lock ring and seal from AutoZone - Spectra Premium Fuel Tank Lock Ring, P/N LO03
(1) Fuel tank filler neck grommet from AutoZone - Spectra Premium Fuel Filler Neck Seal, P/N FNA03
(1) Fuel pump to hanger S hose from Walmart (quicker shipping) - Quantum P/N HFP-RH2
(1) Walbro GSS340 sock filter (strainer) from www.walbrofuelpumps.com - Walbro P/N 125-157
(1) Walbro GSS340 replacement electrical connector plug from Amazon - Ballenger Motorsports P/N CONN-76039 (fits 10-12 ga wire)
10 ga PTFE jacketed wire - Mar Vac Electronics (10' of black and 10' of orange)
(2) Rubber grommets 3/16" ID from Lowes - Lowes Item #423561
(1) 30A Bosch relay - I bought a lot of 30 a few years ago and still have some left so I’m going to replace the one I put in years ago.
New stuff due to going to a different hanger and upgrading the fuel lines:
(1) Pro-M fuel pump hanger with 3/8" fuel lines and 6AN fittings - Pro-M P/N HANG
(2) 25' lengths of 3/8" plastic fuel line from Amazon - Dorman P/N 800-072
(2) 5/8"(16mm) ID Heat Shielded Fire Thermo Armor Fire Sleeve Silicone Coated Fiberglass for Automotive Hose Lines & Electrical Wiring Black, 5 feet - BSTFLEX P/N FIRES16MM
(1) 3/8" ID Black Silicone Coated Fiberglass Heat Shielded Sleeve Fire Thermo Armor for Hose Lines & Electrical Wiring, 5 Feet from Amazon - KRD Performance M/N HSA-10-5_BK
(2) 6AN Male to 3/8" SAE Quick Disconnect Male Push On EFI Fitting Adapter Aluminum from Amazon - Evil Energy No P/N
(2) -6AN Female to 3/8 Male EFI Adapter from Amazon - Fragola P/N 491995
(1) Fuel Line Straight Quick Connector - Adapts 3/8 In. Steel To 3/8 In. Nylon Tubing from Amazon - Dorman P/N 800-082.5 (box of 5)
(1) Fuel Line 90 Degree Elbow Quick Connector - Adapts 3/8 In. Steel To 3/8 In. Nylon Tubing from Amazon - Dorman P/N 800-086 (single)
(1) 3/8" Fuel Filter (quick disconnect on both ends) - WIX P/N 33243, Good for 75 psig
(1) 3/8" Inch Stainless Steel Cable Clamp, Rubber Cushioned Insulated Clamp from Amazon - Lokman P/N LK-88 (20 Pack)
(1) 3/4" Inch Stainless Steel Cable Clamp, Rubber Cushioned Insulated Clamp from Amazon - Lokman P/N LK-88 (20 Pack)
I watched a few videos of increasing the wire gauge size to the pump and this guy always cracks me up and he had a video on it. About the only thing I am using from his video is drilling the rivets on the factory white connector and running the wire through those holes. Watch the rest of the video at your own peril...
Most of the videos reused the wires on the hanger which I do not want to do. I am going to use his trick on drilling the rivets, enlarging the holes for 0.1875" ID grommets, and passing the 10 ga wire through them. If the wire is a tight fit through the grommets a little dish washing liquid may be in order. The PTFE jacket on the wire will be really slick so it may pass right through. Did a bit of reading on what to seal the grommet and wire to the hanger and the resounding answer was two-part epoxy. I plan on covering the entire grommet as they are just rubber and the gasoline will eat them up over time. I am only using them for chaffing on the wire so covering them top and bottom with the epoxy is not an issue. I am also going to cover the end of the crimp connectors that go into the fuel pump connector with the epoxy as I do not want fuel to migrate up the wire. This will get the pump installed into the tank and next will be getting the wires into the trunk.
I will be installing a Delphi Weatherpack connector so that I have a quick disconnect under the car to get the tank out. Just in case someone does not know what a Weatherpack connector looks like (finding a smaller image was taking too long):
I will use the 12V+ and ground in the stock wiring harness to trigger the 30A Bosch relay that will be mounted in the trunk. The relay will be mounted behind the panel that covers the rear tail lights and I will ground the pump at the same location. I will run a 10 gauge wire from the battery back to the relay and fuse it up by the battery with a 15 amp fuse and see if the inrush when the pump starts pops that or not. Most say that they have 10 amp fuses and have no issue but all the new wiring will support more than 15 amps so things should be safe.
The whole idea behind this is to keep the voltage as high and steady at the pump as possible. With the age of the wiring on the car, the factory power wire being 14 gauge, the power wire passes through five connectors. Power starts at an 18 gauge fusible link that is at the starter solenoid on the inner apron, goes to the fuel pump relay, then to a connector in the passenger kick panel, then to a connector in the driver kick panel, then the inertial switch connector, then the disconnect plug between the body harness and the tank harness under the car, then the connector on the fuel pump hanger, and then the fuel pump connector. After I rewire it there will be a fuse, relay connection, weatherpack connector, and then to the pump connector. My guess here is right now it is loosing over one volt based on all the connections and the length of the wire. The additional volt will basically net the flow rate about 35 lph at 45 psig.
Anyhow, I will update this as progress is made. Right now I have the tank out and the hanger stripped. Progress will depend on how busy the week is at work.
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