Single GT-40 fuel pump install

[juno]

Installing a single GT-40 fuel pump in a Mercury Marauder


I will be installing a single turbo kit on the marauder. As part of the fuel system upgrade I have chosen to use a stock GT-40 pump out of the ford supercar. Test have shown this pump to flow from 430 lph at 40 psi to 290 lph at 90 psi at 12.6 volts. Based on the modest boost I will be running (6-9 psi) I hope this pump with 60 lb injectors will supply sufficient fuel for my power levels (400 –460 rwhp). The dyno will be at least a month away, but I will report the results. Right up front I would like to thank the MM.net members who gave me physical, technical and moral assistance!!

Ford part numbers are 4G7Z-9A407-CA or pfb81. Cost about $80.

The GT- 40 pump comes with a different fuel line (longer and with a 90) and separate connectors. You will need to have two shielded connectors to fit the GT-40 tabs and a very small stainless hose clamp for the fuel line. You can pick your sizes once the GT-40 pump arrives. I fully expected to have to drop the tank to install this pump, but after some teleconferencing with Shakes26 I learned that Carfixer replaces the stock pumps with the tank in place and the frame on a lift. I used jackstands, and while it was a PITA, it is doable. Ensure you have less then 1/2 a tank of fuel . A ¼ or less is best.

1. Remove the plastic basket from the GT-40 pump. Remove the fuel line from the GT-40 pump by cutting the metal band off.

GT-40 PUMP


2. Remove the negative lead on the battery

3. Place the rear of the car on Jackstands

4. The fuel pump assembly is located on the front of the fuel tank just above the pumpkin. With the axle hanging it is possible to remove it with the tank in place.

5. Disconnect the power to the fuel pump. (note: if you want to disconnect the fuel line and can find the disconnect for the fuel level sender then you will be able to remove the entire assembly.)

6. Remove the six bolts holding the assembly in place. I believe they are 8 or 10 mm. You will need a long (> 6" extension to reach past the axle.)

7. I had to remove the hanger on the passenger side MEG tip to allow it to move a few inches to get the assembly out.

8. Wiggle the cover to loosen the assembly. Gently remove the assembly taking great care to not bend or damage the lever for the fuel sender float. I chose to leave everything hanging.

STOCK PUMP ASSEMBLY WITH FUEL SENDER MOVED


9. Cut the tie wrap from around the assembly.

10. Remove the fuel sending relay for access to the fuel line/connector.

11. Remove the screw from the band holding the fuel pump on and remove the band.

12. Disconnect the electrical plug from the fuel pump. Cut the metal band on the fuel line very carefully so as not to damage the stock line. Remove the pump by pulling it from the stock line.

STOCK PUMP REMOVED - note the electrical plug


13. Remove the sock and remove the rubber "basket" from the stock pump. You will reuse the basket on the GT pump. The GT pump is slightly smaller in diameter. I used a tie wrap to attach the old basket to the new pump.

Stock (left) GT-40 (right)


14. Cut the stock connector from the existing wires, as close to the connector as possible. Attach a shielded connector to each wire.

15. With the new sock and old basket on the GT-40 pump, reinstall it on the existing fuel line using a stainless steel hose clamp.

16. Connect the wires. One GT-40 terminal is marked positive. The wires I had at my pump were BLACK and Pink with brown or yellow stripe. It was hard to tell after being discolored by the fuel. My BLACK wire was the negative and the other was the positive.

GT-40 pump installed. Note the new electrical connectors.


17. Reinstall the bracket and any tie wraps.

18. Reinstall the fuel sender.

19.Carefully insert the pump back in the tank.

20. Tighten down the cover assembly.

21. Reattach the MEG hanger.

22. Connect the battery and start the car.

23. CONGRATULATIONS- you now have a supercar fuel pump in your marauder!

[juno]

OK, how do I make the pictures show up??? Anyone??

Edit. Dohhhhhhhhh! Never mind.

[SergntMac]

Nice coverage of a challenging mod, congrats!

Any thought to improved fuel line to the front, and removal of the 90 degree bends at the filter?

[RR|Suki]

anyone know what the flow is compared to the SVT focus set up

[Zack]

Ive heard nothing but awesome things about the gt-40 pump.

[Zack]

When you hooked the line up to the gt-40 pump, you DID reinstall or replace the metal clamp that holds the fuel line on, right? I dont see it in the pic.

[juno]

You can't see it behind the connectors, but I did use a very small SS hose clamp as iin my instructions.

When you hooked the line up to the gt-40 pump, you DID reinstall or replace the metal clamp that holds the fuel line on, right? I dont see it in the pic.

[RR|Suki]

That's alot of flow, I think I'd like to try this aswell if my flow turns out to be less than I like when I go to get tuned

[FordNut]

Thanks a lot for the detailed write-up!

[juno]

I think the single SVT Focus is 143 LPH at 80 psi.
Dual Cobras are 268 lph at 80 psi
Single aviator is 270 lph, but a lot of current draw.
Single GT-40 is 324 LPH and the current is lower then the aviator.

per the testing info I have.

It does seem kind of too good to be true, but we will see when I hit the dyno.

anyone know what the flow is compared to the SVT focus set up

[RR|Suki]

I think the single SVT Focus is 143 LPH at 80 psi.
Dual Cobras are 268 lph at 80 psi
Single aviator is 270 lph, but a lot of current draw.
Single GT-40 is 324 LPH and the current is lower then the aviator.

per the testing info I have.

It does seem kind of too good to be true, but we will see when I hit the dyno.

That's hot man

[juno]

I would love to do that if I could gather all the fittings. I do not think it is necessary for the HP levels I will be at. But....

Do you think the extra volume in the lines and rails could help mitigate a fuel problem when coming in and out of the WOT tables?

Nice coverage of a challenging mod, congrats!

Any thought to improved fuel line to the front, and removal of the 90 degree bends at the filter?

[SergntMac]

I would love to do that if I could gather all the fittings. I do not think it is necessary for the HP levels I will be at. But...Do you think the extra volume in the lines and rails could help mitigate a fuel problem when coming in and out of the WOT tables?

Honestly, no, I don't think so. "Floating the tables" is an issue between the EEC and your right toe.

If you're using 60# injectors, the supercar pump stats say you should have plenty of fuel on hand through the 7K shut off. It's on my mind that the areas I mentions are your only potential bottlenecks, moreso the 90 degree bends than the fuel line to the rails.

My lines are stock, but I fixed the bends with a Reinhart fuel filter kit, and I'm getting a solid 39 pounds across the injectors at 6200 RPMs, on twin Focus pumps, BAP and modified FPDM. Peek here?

http://www.mercurymarauder.net/showc...c=3&userid=392

It never ceases to amaze me how the mods morph, and morph again, into the best (and cheapest) solution. I went through the stock pump, a Walbro 255, skipped the twin Cobra due to finances, and settled on the twin Focus/BAP because it was do or die. Now, another down and dirty (and cheaper and better) solution. Oh well...Such is life modding a Marauder.

IMHO, sound like you'll be fine with your design, congrats again.

[mad1stgen]

I'd love to see those pics, but only red XXXs so far.

[juno]

Yeah, what happened to my pics? They are still in the gallery.

I'd love to see those pics, but only red XXXs so far.