fuel pump question (carb converted)
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fuel pump question (carb converted)
i am running a red holley (7lbs.) fuel pump on my carbed '85.
i keep popping the fuse on it, no matter what size fuse i run, it pops after a couple minutes. my question is this... should the pump have a relay wired to it? has anyone here ever hooked one up and how exactly did you wire it?
thanks greg
i keep popping the fuse on it, no matter what size fuse i run, it pops after a couple minutes. my question is this... should the pump have a relay wired to it? has anyone here ever hooked one up and how exactly did you wire it?
thanks greg
Thread Starter
Race Director
Joined: Mar 2002
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if i still have it, it will be in a box in the garage. i was having a hard time the last time i worked on it getting the rubber ends to work right. i could send you the tube if you want to monkey around with making your own ends. that is if it's still out there, when i built the new garage i tossed out a bunch of stuff. i can look.
can i rewire the existing relay to work with the new pump? would you know how to wire that up?
can i rewire the existing relay to work with the new pump? would you know how to wire that up?
Thread Starter
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on the old relay there are 5 wires
orange to battery feed
black/white to ground
red circuit #490 to ?
dark green/white circuit #465 to ?
red circuit #458 splices to the burn off module and ?
can anyone fill in these blanks?
i have a couple of pages missing from my manual.
orange to battery feed
black/white to ground
red circuit #490 to ?
dark green/white circuit #465 to ?
red circuit #458 splices to the burn off module and ?
can anyone fill in these blanks?
i have a couple of pages missing from my manual.
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Team Owner
Joined: May 2002
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
on the old relay there are 5 wires
orange to battery feed
black/white to ground
red circuit #490 to ?
dark green/white circuit #465 to ?
red circuit #458 splices to the burn off module and ?
can anyone fill in these blanks?
i have a couple of pages missing from my manual.
orange to battery feed
black/white to ground
red circuit #490 to ?
dark green/white circuit #465 to ?
red circuit #458 splices to the burn off module and ?
can anyone fill in these blanks?
i have a couple of pages missing from my manual.
Dark green is the ECM input. Put 12V to this and the relay is activated.
OR... Run hot 12V to the dark green, then put a switch on the black wire to activate the relay. This is the more common method, less fire hazard.
The fat red wire powers the pump. Put your fuse on this line. The skinny red I think is for the diagnostic connector.
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From: Database Error Indiana
You are making this way too complicated. I have used Holley pumps on several cars. No relay. Just run a nice heavy power wire (switched) and a good ground. If you are blowing fuses, you have a short circuit, for sure.
Team Owner
Joined: May 2002
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
I spend about 3 hours researching pumps to do an EFI swap on a dual tank truck.
End result: Don't use an inline pump.
It shouldn't be nearly as loud in tank. Also there's no need to go with aftermarket, there's plenty of OEM Airtex, Carter and Bosch pumps that will fit the bill, and in stock at your local parts store.
End result: Don't use an inline pump.
It shouldn't be nearly as loud in tank. Also there's no need to go with aftermarket, there's plenty of OEM Airtex, Carter and Bosch pumps that will fit the bill, and in stock at your local parts store.
Race Director
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From: Database Error Indiana
I spend about 3 hours researching pumps to do an EFI swap on a dual tank truck.
End result: Don't use an inline pump.
It shouldn't be nearly as loud in tank. Also there's no need to go with aftermarket, there's plenty of OEM Airtex, Carter and Bosch pumps that will fit the bill, and in stock at your local parts store.
End result: Don't use an inline pump.
It shouldn't be nearly as loud in tank. Also there's no need to go with aftermarket, there's plenty of OEM Airtex, Carter and Bosch pumps that will fit the bill, and in stock at your local parts store.
Now thats good advice.
Team Owner
Joined: Jan 2003
Posts: 20,292
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From: Summerland B.C. Canada
I ran an electric fuel pump on my 68 Camaro for 8 years, without a relay. I just had it wired to ign on power. I never had a working fuel gauge in that car, when I heard the pump get really loud, I knew I had less than a mile before I was dead. 8 years and never ran out of gas, damn I was lucky.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
I ran an electric fuel pump on my 68 Camaro for 8 years, without a relay. I just had it wired to ign on power. I never had a working fuel gauge in that car, when I heard the pump get really loud, I knew I had less than a mile before I was dead. 8 years and never ran out of gas, damn I was lucky.
nincompoop, can I have your stock pump for my project? Also, do you know the output pressure of the stock pump? I assume you looked into this before getting the Holley.
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i wanted to run a new system that was not connected to any of the existing electrical in the car. the wiring is so bad in this POS.
Team Owner
Joined: Aug 2000
Posts: 40,156
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From: San Pedro CA
I hear you about the factory wiring. I am willing to bet that the old harness was 90% of the problem towards your drivablity.
I would make a harness for the fuel pump, but make it emulating the OEM design. There is something nice about a relay, for electrical safety, vs a straight wire.
I would make a harness for the fuel pump, but make it emulating the OEM design. There is something nice about a relay, for electrical safety, vs a straight wire.
