Chevy_man_88

I got done with the carb swap, my question is how do I rewire the fuel pump so it can turn on with the key on engine off? Any diagrams or directions?

Schurkey

Simple solution:

Find a terminal in the fusebox that is "hot" in "Run" and "Crank", but not in "Accessory" and "Off". Route power through an oil pressure switch so if the engine stalls, the pump shuts off. There's almost certainly a suitable oil pressure switch on the vehicle as standard equipment from the TBI harness.

Better solution:

Take power from "Crank" on the ignition switch, route directly to pump, or via a relay. Pump runs in Crank. Wire probably needs a diode to prevent back-feeding the "Crank" circuit when the "Run" circuit takes over powering the pump.
Take power from "Run" on the ignition switch, route through oil pressure switch, again relay optional. Pump runs in "Run" only if there's oil pressure. Again, wire should have a diode to prevent back-feeding from the "Crank" circuit.

GM is known for using too-thin wire to power the in-tank pumps. "I" would use 12-gauge on both the power and ground, instead of the ~16-gauge GM puts in.

And, of course, you're going to have to regulate down to a fuel pressure the carb needle 'n' seat 'n' float assembly can manage to control.

I still say it was a mistake to disable the TBI in favor of a carb. What are you using to lock the torque converter clutch? Does the trans have shift solenoids? Will the speedo and odometer work without the computer?

91 camaro racer

iTrader: (2)

yes you will have to regulate the fuel pressure down to around 6 psi depending on what carb you put on. you will want a return style regulator to feed the excess back to the tank. Mallory 4309 is a good popular choice but any return style will work fine.

i wouldnt say it was a mistake for him to go from tbi to carb, i did the same years ago. some people are just better with tuning carbs then trying to burn proms and tune it that way. there are many options to use to lock the TCC, or just leave it unlocked. i left mine unlocked and even with a 3600 stall convertor i havent had any issues and the trans fluid temp doesnt go above 170. yes the speedo and odometer will still work. that is ran off of a different harness. all the gauges still work.