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Hi all, hope your well
I have an 07 Z06, car has a big fuel system (id1050x, dual fore walbro 525 hellcat pumps)
I was driving, put the car in neutral to coast to a stop, and the car slowly died on me. Would not start back up.
The fuel Schrader valve had no fuel coming out, the car has fuel. Put a new fuel pump relay, adjusted the pins below the relay and still nothing.
The fuel pump has probably 40-60k miles on it.
The fuel wire for the main wiring harness seems to be aftermarket.
I put power to the relay and nothing came out of the fuel line.
Is the only next option to drop the tank and see if the pump is getting power, or if it needs to be replaced.
Or is there a wire that does along the body of the car that could be causing this issue that I should check?
Thanks
Last edited by 26mconnolly; May 25, 2026 at 08:35 PM.
You need to TEST all 4 terminals of the relay...do you know how to check the load and control sides of the relay ??...all you need is a 12 volt test light...you also need to voltage drop the fuel pump circuit also.
You need to TEST all 4 terminals of the relay...do you know how to check the load and control sides of the relay ??...all you need is a 12 volt test light...you also need to voltage drop the fuel pump circuit also.
I bypassed the relay and gave it 12 volts yesterday, still wouldn’t start
If you have high resistance in the circuit giving it 12 volts doesn't do anything for you...the pump is not getting the proper current....you need to check the positive and negative sides of the pump from the battery to the pump...since you pump is not working you have to substitute the pump with a headlight bulb or you won't be able to voltage drop the pump...if voltage drop is good and pump is inop you have a bad pump...I don't know if your pump has aftermarket wiring but X459 is where you need to check...you have 3 other terminals of the relay to test.
If you have high resistance in the circuit giving it 12 volts doesn't do anything for you...the pump is not getting the proper current....you need to check the positive and negative sides of the pump from the battery to the pump...since you pump is not working you have to substitute the pump with a headlight bulb or you won't be able to voltage drop the pump...if voltage drop is good and pump is inop you have a bad pump...I don't know if your pump has aftermarket wiring but X459 is where you need to check...you have 3 other terminals of the relay to test.
The 20 amp fuse is upstream of the relay so the fuse isn't your issue but still needs to be looked at...resistance causes heat and that is why your fuse is over heated...you need to look into the fusebox...are you 100% positive you fed the right terminal 12 volts ??...if you take a test light connected to B+ and probe terminal 87 (G7) the test light should illuminate as it will finds a ground through the windings of the fuel pump to ground !!
The 20 amp fuse is upstream of the relay so the fuse isn't your issue but still needs to be looked at...resistance causes heat and that is why your fuse is over heated...you need to look into the fusebox...are you 100% positive you fed the right terminal 12 volts ??...if you take a test light connected to B+ and probe terminal 87 (G7) the test light should illuminate as it will finds a ground through the windings of the fuel pump to ground !!
it’s got 2 big fuel pumps so it has aftermarket wiring. It has its own ground, and it’s powered right to the alternator lol
it’s got 2 big fuel pumps so it has aftermarket wiring. It has its own ground, and it’s powered right to the alternator lol
Unfortunately you'll have to diagnose this yourself as I don't know how this is wired...maybe you can provide a diagram of the circuit !!...so instead of coming from B+ as in the schematic it is coming from the alternator B+ and still going through the 20 amp fuse and relay ??...how many amps do these pumps draw ???...my stock 08 pump draws a little over 8 amps...the more resistance you have in the circuit coupled with the increased current flow you have from these aftermarket pumps will lead to what you see with your fuse...the pump circuit is very easy to diagnose as long as you have a basic understanding of electricity...if you are more of a "wrench turner" than a diagnostician I'd seek out an auto electric shop in your area...if your voltage drop is negligible then you have bad pumps...without testing you are just guessing...you don't want to remove the pumps needlessly...I don't know if you or someone else did the pump installation....the last member with an inop pump had a burned terminal at X184.
07 Z06 fuel issues.
