grove

iTrader: (3)

swapped tbi to carb. almost finished but, i cant get the fuel pump to come on. ive tried bypassing the fuel relay by put a 12v source to the tan/white wire, didnt work.
i do not have a oil pressure switch. it was removed when i had the engine sent to the machine shop.

on the fuel relay connector, the only wires that are still connected to the car are the red, orange, and tan/white. the green/white and black/white were cut so the engine harness would come out.

ive been battling this problem for 2 days, and i dont have much time left here in florida. only about 4 days left.

camaronewbie

I believe you need the black/white - it's a ground for the relay.

But - regardless of having an oil pressure sending unit or not, you should still have the wires for it, right? If so, you can make use of the relay, and the OPSU wires. Rig the relay so it gets it's ground, and gets a 12v+ ONLY when the key is on - this activates the relay. Then put the OPSU wires on the other 2 prongs - they will in effect get connected to one another when relay is activated. The OPSU wires you want are the 2 larger ones, I believe one red and one orange. With this setup, the fuel pump will only run while the key is ON, but won't run in the ACC posistion.

White'89

iTrader: (8)

Sounds like you did something many will frown upon you for doing. CUTTING is a no no.

grove

iTrader: (3)

sooo i need to plug the fuel pump relay back into the connector right?

which wires went to the OPSU? i dont remember and some my labels had fallin off over time. the car has been sitting for about 2 years now.

aremy10

iTrader: (3)

you should be able to just put a switch between the orange wire and the tan/white wire. mine is orange to a grey wire, but mine is a 91 so maybe they have difrent colored wires. the red is for the prime switch(witch you dont need. if you put a switch between the two wires mentioned, you dont need the relay

grove

iTrader: (3)

good news, got power to the fuel pump. we had to disconnect the fuel pump to find out which wire and read out the wires. 12v to the tan/white. the problem was the fuel pump went bad while it sat for 2 years. oops. soo tomorrows agenda clean the inside of the tank, put the new pump, and cross my fingers and hope the new motor fires up.

88sporty

not to be bringing up old news, but i have an 88 sc that im swapping in a 79 305, the fuel pump will run when directly connected to the power and i have everything connected, and no breaks in the wires. the guy i got the car from hacked out the old engine wire harness, i switched it from my 85 into the 88 (including the ecm) but regardless i still cant get the pump to come on with the key. the relay we moved into the car is good, the 85 was a running car. can anyone help me out?

camaronewbie

Was the 1985 car a carbed car? If so, it wouldn't have fuel pump wiring - 1985 carbed cars had mechanical fuel pumps.

88sporty

I should have been more specific, both cars had a factory fi v6, the 85 had the engine and trans which is being donated to the 88 (the 88 isn't rusted out). When running the 85 had the electric in tank pump running up to the mech pump on the block. Aa bit much I know, I just haven't changed it yet