TP355Z

I'm in the middle of a carb swap and need to know how to deal with my fuel pump. Does it have to be hot-wired with the TBI/EGR/distributor systems removed? Where does the computer get the signal to run the pump after the initial 2-3 second run when u turn the key (before the car turns over)? Help me out guys, I'm stumped.

Ty

scauffiel

Why do you guys insist on removing all of the wiring? Blows my mind. Once you start tearing out crap, you remove any kind of "common ground" with the folks around here and have a helluva mess. Leave the wiring in place. Hook up carb. Install regulator. Reduce pressure to 5-7 psi. Done deal.

S.

TP355Z

hold on buddy, i haven't removed any of the wiring. I just removed the tbi/distributor/egr (the hardware - the wiring is still there, the whole harness is still in tact) - but I figured that the computer got the signal to run the pump from the distributor spinning or something. How does it work?

dimented24x7

iTrader: (2)

The computer gets its signal that the engine is cranking/running from the dist. reference pulse. When it sees the pulses, the computer triggers the fuel pump relay. The pump will still operate the way it is. There is a backup switch above the oil filter that closes at, i think, 4 psi. The stock oil pump will have to turn a bit to build oil pressure before the car starts but its not too big of a deal. If the motor has a high pressure/high volume pump it will close almost immidiatly. My goodwrech builds around 35 psi when cranking and it would close the switch as soon as the engine cranked.

TP355Z

hey demented - (i think you're my new best friend)

so what you're saying is that the sensor above the oil filter (which i thought was an oil-dummy-light-sensor) is actually for the fuel pump?

As long as I leave that switch hooked up, my fuel pump needs no tweaking then right? (i have a high pressure oil pump too...)

Ty

Brent

iTrader: (1)

NEVER EVER hotwire the fuel pump to the ignition switch.

If you have an accident and the fuel lines are torn there is nothing to stop the pump. You could have a roaring inferno in short order.

Like was mentioned, use the factory oil pressure switch to run the pump.

MrDude_1

you can.

just use a rollover switch like fords have.

chevypower

That switch is the oil pressure/fuel shut-off sensor. It does also work your oil pressure guage in the dash. 4psi is also correct.

TP355Z

so bottom line: as long as that sending unit above the oil filter on my 1988 tbi car is hooked up, my fuel pump will run, right?


Thanks fellas

ty