Frankenpump----It's alive!

I have had a long and frustrating path to trying to get a decent fuel pump for my 96 RMW.

I had the stock pump at 140K miles with a jumpy sending unit, functional pump but no idea how much longer it would last.

Ordered and received a Delphi pump and sender ass'y and it came as one for the sedan, even though they say it is for wagon. Wouldn't accept it as a return as it was over 30 days before I went to put it in.

Ordered a Selphy pump and hanger at Rock Auto listed as distributor closeout, and it showed up as a typical cheapo Ultra Power Asian unit. Did get credit for that one.

Finally decided I had to use the original hanger ass'y as it was OK, minor tube rust, except for the sender.

Ordered and received a new Delco pump to use.

I have read a couple of places you can't swap the sending units between OEM originals and newer aftermarket, but the Delphi sender which was silky smooth operating dropped right in place no problem. Except it didn't work right at the cable end and read open all the time. It turns out the changed the plug at the top of the hanger, effectively just moving the pins 180* in the existing setup, and then turned the plug latch catch 180* to match. If I plugged the Delphi plug into the OEM handger turned 180* it all worked fine. Except it needed a retainer. I pried the springy nut off the Delphi with as little as possible damage (wouldn't be good enough to hold the plug fuel tight though) straightened it as best I could and put over the existing spring nut in the original hanger, but turned 180*. Held the plug fine. Put in the new pump and output seal that came in the kit, used the Delphi new spring and clip and gave it a test in a bucket of mineral spirits where it pumped fine. Sensor read 2 ohms to 95 ohms on my old Fluke meter.

Put it in the tank and pump ohmed out fine, but sensor had very narrow range. Took it out and tried again with different but still bad results. Finally, I left the meter hooked up to the sensor as I put it in and wiggled and wobbled it until the sensor read the lowest ohms at about 5 ohms. Float must hit the bottom of tank, like it should. Bolted it down and flipped the tank over and went to full ohms so so good to go and I put it back in the car.

Added about 3 gallons of gas and it read 1/8 tank so reading good at least that far. 45 psi on battery only no engine running 47 psi hot at 700 rpm with no vacuum. Very steady pressure.

So Frankenpump looks to be working OK with a GM hanger, Delphi level sensor, and Delco pump.

I found an EP376 pump on Amazon that purports to be genuine GM. It lists USA as country or origin but is actually made in Brazil. Maybe that would be OK. Is the pump you bought USA?

dwardo wrote:

I found an EP376 pump on Amazon that purports to be genuine GM. It lists USA as country or origin but is actually made in Brazil. Maybe that would be OK. Is the pump you bought USA?

Nope, mine was also Brazil. It appears to be identical to the OEM one that was in the car, though.

Good! Ima buy one just in case.

I figured I would bring this back up to update.

Spring is here and took RMW out to bed new brakes and then off the gas station to fill and see how the gauge is working.

I had added about 5 gallons to test the pump and running pressure so it had some gas and read on the gauge at just over 1/4. I figured it would take around 14 gallons to full and it took 15 so good there. Gauge went to a bit above full mark so good there. I know the empty to 1/4 is good from the hand filling so it appears the gauge is working near perfectly. This is a Delphi sending unit put on the original hanger with a new Delco pump. It did take me 3 tries when I put the pump in the tank before the float output resistance checked right when I flipped the tank to check full to empty resistance.

Pump is running at high end of pressure spec and car runs very well.

After hearing all the horror stories about gauges not working right after new pumps put in, it was a relief to see it actually is better than it was before the change by a bit.