1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

EFI Fuel Pump Setup

Old 06-30-12, 11:08 AM
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EFI Fuel Pump Setup

I'm trying to price out a parts list for someone to convert there car to EFI with ITB's but I'm not sure what needs to be done on the pump side. The car is a 12A. Is the OEM fuel pump intank and can it be replaced with something like walbro/supra pump/aeromotive stealth, or would it have to be an external like a bosch 044? I'd like to get an overkill pump like the aeromotive stealth or something similiar and run 60 PSI base fuel pressure.

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Old 06-30-12, 01:51 PM
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External or "inline" is what you should look for. Also look for a GSL-SE tank because it has a sump cup. Not as large as an FC, but it has one.

Everyone else will tell you to mod the tank by cutting it open, adding a large sump cup and an in-tank fuel pump. I'm like "why?". Due to the noise? Um, my inline walbro 255 is not loud at all.
Old 06-30-12, 04:52 PM
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I cut open the top of my fuel tank simply to add a sump and larger feed and return lines. I have an external/in-line walbro 255 mounted roughly in the stock location, ran new 5/16" hard lines from pump up to firewall, and return from firewall to tank. And for a small bit of safety used the original fused power circuit for the pump as a ign on signal for a 20a fuel pump relay( didn't feel comfortable using a 10a fuse to power a walbro)
Old 06-30-12, 06:16 PM
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Thanks guys, inline it is. I wonder if the Walbro 255 will be happy sitting at 60 PSi?

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Old 06-30-12, 09:52 PM
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should be, i think they are rated up to 80ish max
Old 07-01-12, 08:46 AM
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Originally Posted by Jeff20B
Everyone else will tell you to mod the tank by cutting it open, adding a large sump cup and an in-tank fuel pump. I'm like "why?". Due to the noise? Um, my inline walbro 255 is not loud at all.
I have a 12A tank and an external pump.

With less than 5 gallons in the tank, I can get my engine to cut out with a hard left corner. Takes some doing, but it's possible.

Gets progressively worse, of course, as the tank gets lower.

The fix is to use a surge tank. I think the best option would be to grab the fuel pump box from an A2-chassis Golf/Jetta, preferably a 16v since they had the biggest pumps, next preference is anything else with CIS. (CIS runs at ~90psi, so the pumps flow torrents at EFI pressures) The pump box is a 1 liter container with the fuel pump mounted inside, with an inlet from the lift pump, a high pressure outlet to the rail, a return from the rail, and a return to the tank.

Looks like this: eBay auction

Downside is that it REQUIRES a lift pump to function, and the box itself might be difficult to package under an RX-7. But the bonus is that the thing won't run dry even if the lift pump sucks air, since the return from the engine goes to the box.

Yeah, turd polishing is great. On the other hand, I simply live with the stutters on the street, and keep the tank between 3/4 and 1/2 full in competition. More fuel than that causes it to slosh out of the vent hose and spray onto the header. (Some dumbass de-smogged the car, so the tank vent just breathes free)
Old 07-01-12, 08:50 AM
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Originally Posted by Sgt.Stinkfist
And for a small bit of safety used the original fused power circuit for the pump as a ign on signal for a 20a fuel pump relay( didn't feel comfortable using a 10a fuse to power a walbro)
My Bosch pump draws 2 amps.

Just sayin'.

How big is your turbo that 8mm lines aren't big enough? Stock lines are good up to about 400hp.
Old 07-01-12, 11:07 AM
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^ at 65 psi a walbro is rated at a 10.4 amp draw
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