Tell me if this sounds like a fuel pump issue (Page 1/1)
qwikgta NOV 20, 10:11 AM
88 GT with 2004 3800 N/A motor. Engine stopped running the other day. Trouble shooting leads me to think fuel pump. I lift the car, drop the tank and find that the PO had installed a second fuel pump relay, he wired up the fuel pump bypass that is listed on the Sinister Performance web site. If your not familiar with it, the theory is that the power to the pump has to run from the battery to the fuse box under the dash, then thru the C203 wire to the relay at the rear firewall, then back the same way. Ryan's bypass is to run a relay off the battery to the pump with out having to go up to the factory fuse box and back. Its a great idea and I now have done it to all my cars.

OK so after i drop the tank and find the 2nd fuel relay is bad, i install a new relay and figure that b/c i have the tank down, I may as well install the new pump. So I do, and after installing everything back into the car I have an issue with it. When I drive the car it drives fine until I floor the gas, and it stalls, sputters and drives like crap. if I get into the gas slowly, it goes like a bat out of hell. So, if i'm driving along at 45 and floor it, same thing, sputter, sputter, sputter, but as soon as i start to lift my foot, gas flows and it takes off.

The pump was a brand new GM 3.8L pump for a Turbo Pontiac Trans Am, I've used them in most of my swaps and they work great. But i'm thinking something may be wrong with this one.

What do you all think? Thanks in advance.

Rob
Dennis LaGrua NOV 20, 11:15 AM
First step: Check fuel pressure.
Second step: Check for voltage at the fuel pump feed.
theogre NOV 20, 07:53 PM
See my Cave, Electric Motors

Iffy wiring can cause low volts and burn motor and everything controlling it.

Plus Most relays aren't rated for DC power.
Find a OE grade pump relay from a good brand from a real store.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave