Fuel Pump Problems ECM? OIL Pressure sending unit? Both?
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Fuel Pump Problems ECM? OIL Pressure sending unit? Both?
Hi guys I've been having trouble with my 1986 IROC Z28 with a 350 roller crate motor in it (the guy that had it before me did a boat load of janky wiring). The fuel pump is wildy intermittent I drove it all day yesterday and it ran fine all day and didn't die on me. Sometimes there are days I start it and it dies right out of the driveway and won't restart for days. I checked the OPSU and it had a slightly loose connection and figured maybe that was it end of story.... Wrong.... It ran fine for about 45mins but just as I headed home BAM!!! DEAD AND WONT RESTART.... Had to tow it back to the house the fuel pump wouldn't come on at all. I also have a question about the OPSU is it supposed to have 12v constant?? Looking forward to hopefully a solution Thanks!!!!!
Supreme Member
Joined: Jan 2006
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From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
Opsutunity Of Pump Slump
Originally Posted by Wyomaro
question about the OPSU is it supposed to have 12v constant?
You need to find out where the pump is losing power.
Grab a piece of sheet metal, drill a few holes, mount 4 LEDs.
You can use LEDs with built-in resistors so they’re ready to use with 12 volts.
Wire A — Connect to pin A of the pump relay.
Wire D — Connect to pin D of the pump relay.
Wire E — Connect to pin E of the pump relay.
Wire P — Connect at the pump.
Mount the panel in the cockpit.
Double-sided tape will work because it’s a temporary panel.
Now, when you’re driving and the engine cuts out, you merely have to glance at the panel to see where the problem is.
But if it won’t prime use a voltmeter see if you have power on pin A of the pump relay orange wire.
It doesn’t matter what position the key is in.
If you don’t have power there check the inline fuse located near the battery.
If there is power there jump pin A to pin E gray wire. for a second or two with a piece of wire.
Does the pump run when you do that?
If the pump will not prime temporarily jump thru a 10 amp fuse, the orange wire to the green wire with the white stripe on the pump relay.
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Happy Racing !
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8 Cylinders, No Waiting
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