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Discussion Starter #1 (Edited)
Here's a crazy one...
I found the source of the fuel odor and its one of the 2 lines or fittings going into the 2003 Corvette regulator I have mounted above the rear on the trunk floor. The regulator is screwed directly to the floor.

Yesterday when I was poking around trying to locate the source of the leak, I could make the fuel pump turn off while I was moving those 2 lines around (as it was running). I've been driving it without issues like the pump turning on and off by itself. its only when I move the 2 lines that it happens.

So tonight I took the regulator down to do 2 things... tighten the fittings on the lines going into it, and to make sure the bracket holding the regulator was well grounded to the body.
Now the pump won't come on at all. I hear the relay...or it could possibly be the pump for only a second when I turn the key on, but it doesn't run.
At least before I made sure the reg was absolutely grounded it would run. What did I do wrong?
 

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Let's see, battery power to the relay, ign sw closes the relay, relay sends power to f/pump, f/pump should pump if the return wire is grounded , at least, in theory.

Unless, the PCM controls the f/pump relay, by applying a low to one side of the relay coil as battery power is on the other side of the coil, then PCM should control the relay.

Then the question is, in the donor car, did the PCM control the relay or did the PCM control the pump?
 

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Discussion Starter #3
The PCM doesn't control it. Strictly the ignition switch and relay.
It has power... all I did was crawl back under there and move the fuel lines a round a little and it worked... just like yesterday. So I took it for a very long drive, turned it off for a while, and the pump ran and started the car again just fine.

It has something to do with the two lines going into the regulator itself. The 2 lines are clamped in several places all the way from the tank so they can't move other than where I wiggle them right at the regulator. What I think is happening is if the 2 fittings right at the regulator touch each other, it works... if they're separated it disables the pump. :confused:
I grabbed the lines and squeezed them together, turned the key and the pump ran.

Odd... and scary. I'm wondering if there's some type of short or grounding going on with the two lines from the tank to the reg. The pump and fuel sender wiring are nowhere near the pump outlet and return fittings on the tank. It's not like they can be pinched... I made absolutely sure of that. I'm wondering if it could be internal at the pump itself now.
And what's even weirder is that once it's running and the car starts, the motion of the car moving doesn't break whatever 'circuit' is being completed to make the pump run.

Oh... and the seeping fuel has been fixed.
:)
 

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The two hard lines are supplying a return for the pump through the clamps to the body.
You might have to ground the regulator/pump and ground the engine completing the circuit.
Separate the two lines and measure each line to ground.
The hot line, the one with power, needs to be grounded, or the reg/pump.
 

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Discussion Starter #5
I didn't do any stray voltage checks yet... wanted to make sure the leak was fixed first.

The regulator and bracket are separated with a rubber gasket between them, but they're bonded together with a strap, then attached to the body at a clean bare metal mounting point.
The clamps are isolated with rubber. There's no metal-to-metal contact between them and the fuel lines.

I'll get back under there tomorrow and do the checks I should have done tonight... I was just too anxious to drive it without my eyes burning for once.
 
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