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Old 04-26-2019, 10:35 PM   #1
70CHEVYBB
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Fuel pump not turning on

Working on my first ls swap. I have a 72 i put a 5.3 in. It cranks over but fuel pump is not turning on. I have a psi harness on the engine and a boyds tank and pump set up. I have power to the fuel pump relay and have swapped the relay with another and still nothing. Any thoughts?
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Old 04-26-2019, 10:44 PM   #2
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Re: Fuel pump not turning on

Is it a intank pump?..do you have power at the pump?...if you have power there it's either wiring or pump
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Old 04-26-2019, 10:55 PM   #3
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Re: Fuel pump not turning on

It is a aero precision pump in the tank. The relay does not even click to send power to the pump
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Old 04-26-2019, 11:01 PM   #4
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Re: Fuel pump not turning on

Have you checked all your grounds for being good and clean and tight?
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Old 04-27-2019, 12:23 PM   #5
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Re: Fuel pump not turning on

Check the wiring to your relay if you have power to the relay and none downstream it is most likely wired incorrect. I would disconnect the the pump to be sure you have the wiring correct at the pump by removing it from the circuit. If it works with the pump disconnected go over your wiring to the pump or bypass the relay to see if it works
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Old 04-27-2019, 02:14 PM   #6
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Re: Fuel pump not turning on

Double check how your hooked into the fuse block.....switch on to #30 ...to the pump #87
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Old 04-27-2019, 04:24 PM   #7
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Re: Fuel pump not turning on

I've never had one, but doesn't a PSI harness come with the fuel pump relay already wired in?
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Old 04-27-2019, 06:50 PM   #8
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Re: Fuel pump not turning on

Quote:
Originally Posted by ls1nova71 View Post
I've never had one, but doesn't a PSI harness come with the fuel pump relay already wired in?
All you have to do is add the power wire and the fuel pump wire. The instructions are very clear and simple. I tried it this morning and the pump ran with the key and the engine tried to start but then fuel pump quit and i lost spark. Very frustrated as i bought a new preprogrammed pcm from PSI when i bought the harness for a trouble free start up and no need to have someone else tune it. I have quadruple check all my wiring so it looks like a call to PSI and bring home a scanner from work monday.
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