Improved FD

my denso fuel pump recently stopped working (0 fuel pressure, it's only about 1 year old!) and I couldn't figure out the problem for a couple of days

after pulling the pump and testing it, I determined that the grounding tab on the fuel pump cover was corroded, so I cleaned it with a die grinder and put some dielectric grease on the plug and the tab

car fired up...

DamonB

Several of us have had that problem.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/no-power-my-fuel-pump-481143/

rajeevx7

iTrader: (11)

Improved FD

update: as I indicated in the first post, cleaning up the ground tab on the fuel pump cover got the engine to start, but it would still die under load...I thought it was one of the relays at first

I jumpered the fuel pump in the diagnostic box and got 12.3 V at the plug...and 10.5 V at the pump itself!! the little connectors go bad after 13 years when exposed to gas all that time (wiring to the pump inside the hatch above the cover looks brand new, and the wiring to the pump itself also appeared to be in good shape)

did a search in the single turbo section and the solution seems to be drilling through the cover, installing new 10 gauge wire to the pump terminals, and junking the little 14 gauge (or whatever they are) wires, plug, and connector that feeds the pump (although I will retain the plug and wires for the fuel tank level gauge)

it never ends with these cars!

Improved FD

and btw, damon, I recall seeing an old thread of yours on the 3k hesitation related to the FP resistor, but I think the poor grounding/wiring of these pumps could be the real culprit

my low to high speed transition had a huge stumble before all this happened

7 BOUND

Just added my supra fuel punmp. My ground was really not that bad, i took a wire brush and hit it up clean and used a thicker 8 gauge wire for my ground.
i got kinda of scrared because i took it out for the first time after the install, and i got a lil worrried becuase i was hearing this hummmming sound, and i came to the fact that it was the fuel pump doing its job, so try a thicker gauge, just cut the ground wire on the harness, and ran the thicker gauge from the pump to one of the studs near that cover plate.

mad_7tist

all you guys that drill into the fuel pump top becareful. the tank pressure can push fuel up the wire sheath and into your trunk. especialy if you live someplace hot like fla. seriously it's fuel and electricity be safe

Improved FD

thanks, man....good idea....the stock ground wire is a complete joke, flimsy little 18 gauge or something

7 BOUND

no problem man> i know that when i did my install, i notice that it was 2 grounds there, 1 was like a 18 guage that mounted on the top part of the cover plate and the other was a 12 guage thats in the harness. i cut the wire in the harness. and cleaned off the top of the 18 guage screw that was kinda bad it had some rust. hope this helps.

Oh yea make sure when you use the studs near the cover plate, scrap off all the paint thats around that stud area, you want a really good contact.

Improved FD

interesting...I didn't see a 12 gauge ground wire in the harness, just the flimsy 18 gauge (?) that goes to the top of the cover, maybe that's part of the problem