i am tired of having problems with crap fuel pumps going out on me and having to get back into the gas tank to replace them. i was wondering if anyone with a tpi has put an external electric fuel pump on their car, id like to hear some experiences and suggestions before i go blindly into this idea. thanks,jj

 

The in-tank pump is used because, being submerged in fuel, the pump has a much easier task meeting the motor's fuel demand, thus allowing use of a smaller, less expensive, pump. Plus being submerged in fuel cools the pump and helps extend its life. This saves the OE money and they dont care so much if you hate replacing their fuel pumps.

However, I do advocate external fuel pumps for FI applications. Both Volvo and Mercedes Benz have used external pumps for years and have proven that they can work very well. And when the external pump has issues, its easy to replace.

I run a dual pump system, similar to the early Volvo design, using a Holley Blue race pump at the tank, a reservoir and an Aeromotive FI pump to supply the rails. Its a very expensive setup, about $500 just in pumps, It works really well and sounds cool though its probably overkill even for my high horsepower motor. Plus, Im somewhat of a nut anyway.

Bosch makes a good external pump that will work fine on a stock TPI. If you run higher horsepower youll need something bigger. You want to mount the fuel pump as low and as close to the tank as possible. Rotary pumps do not produce good lift and perform best when they dont have to pull fuel from the tank.

I have also read here on TGO about guys cutting an access door in the floor of the rear cargo area to make the in tank pump easier to get to. Might be an idea.

A point of interest: regularly running your car low on fuel shortens the life of your in-tank pump.

 

i dont like the oe fuel pumps at all. every time i make a sharp turn at half a tank it sputters. i have replaced the fuel pump 3 times in a month and im getting sick of it. i have an access panel in the cargo area but i still have to remove the inside trim, pull the carpet back, undo the lines from underneath, and remove the fuel pump. from what i understand i would need a pump that " pushes " 225 lph. i know the pump would have to be mounted near the tank and i guess it would have to be lower than the tank for gravity to help. i think it would be easy to " delete" the pump in the tank by removing it and the rubber slide that goes between it and the metal line and putting in a piece of high pressure fuel line to reach the bottom. i am not sure how i would stabilize the line at the bottom yet, or what style pump i should be looking at. i want something way better than stock. i dont like toggles much so i would want to wire it up to the factory harness at the tank for power. i sure cant afford 500bucks for a fuel system but i would like to remedy the pains from weak aftermarket pumps, thanks for the info, jj

 

I used AN 10 braided line for the pick up and fastened it to the OE pick up assembly with hose clamps to keep it securely in place at the tank bottom. I used an AN 10 bulkhead fitting to pass through the top of the tank. Then ran braided line to the Holley pump mounted to the underbody just in front of the tank. then I ran 1/2" fuel line to the reservoir which sits under the front nose piece. the Aeromotive pump is located in front of the LF tire. Most of the fuel system is now braided line with AN fittings. Very pricey stuff. You can certainly do a system like this one alot cheaper than mine.

For fuel pump control, I used the factory relay and upgraded factory wiring. In fact my car runs an ACCEL DFI setup so I used the old MAF burnoff relay(identical to the FP relay) to control the front pump. Both relays are operated by the FP mini relay in the DFI system. I have a momentary "primer" switch below the steering wheel just to help pressurize the system before cold starts but, aside from that, the fuel system basically functions as if it were stock. Sorry I dont have photos at this time. I will be taking some soon and posting them somewhere so others can see what Ive done with this amazing car. If youre interested, I could also post mechanical drawings of the fuel system for you to look at.

As for the less than 1/2 tank cutout. That is alot of why I built this system. Sumping the tank would accomplish the same result. But if you do go external pump you will either need to sump the tank or do a dual pump system with a reservoir like mine to get away from the cutout in turns. I think there must be a baffle that breaks in the tank or some other flaw in your car and mine that causes this. Do all of our 3rd gens have this problem? I havent heard much about it.