I'm not to sure about having to change both pumps. The pump in the right tank (passenger side) I believe is driven off pressure from the left electric pump. It's not a conventional electric pump, only used to transfer fuel to the left tank.

 

Okay I'm outside the box now but why can't I run a inline check valve before the injectors to hold pressure for start up ? Seen it on C5 vets before with big pumps and cams.

 

Yes, the oem pump has a 2 second prime time. Holding the ignition button down (without starting it) for a few seconds before starting it up might help. The loss of fuel pressure can be a bad fuel pump check valve or a fuel injector leaking.

I had a bad fuel pump check valve and could actually hear the fuel drip back into the fuel tank at shut down. Attaching a fuel pressure gauge to the schrader valve at the end of the fuel rail will allow you to trouble shoot both symptoms above. Once fuel pressure gauge is attached, you should have around 58 psi. at idle. Turn engine off and record your fuel pressure readings every 15 minutes. If the pressure drops immediately to 0 psi. mostly likely you have a bad check valve in the fuel pump. If not, record your fuel pressure reading every 15 minutes and see how much drop in pressure you have. Do a search on the normal drop in psi. If a leaking fuel injector is suspect, do a search on testing injector leak down. Basically, you lift the injectors off the intake manifold still attached to the fuel rail. Put paper towels under the injectors and prime the injectors. DO NOT TRY TO START THE CAR! Let sit, record fuel pressure readings and look for an injector leaking fuel onto the paper towel. That's where I would start.

BTW: As mentioned above, the passenger side fuel pump feeds the driver's side fuel tank. The driver's side fuel pump feeds the engine.

 

Because, as Mike says, you really need to prove there is a leak and then isolate the leak.

 

not sure I understand how to hold the button down without starting the engine. Don't press the brake ? The bottom of the start button for acc.

 

or spend $1000 and not solve the problem.
The motor was replaced so the tank would the last place to look for a problem.

 

I'm doing a leak down test tomorrow. Still want to know how to prime the pump

 

Your NOT holding it in START mode, only in ACCESSORY mode for about five seconds, or longer, then the ignition will come on.
Yes, the bottom of the button.

 

Leak down test went from 60 psi to 20 in less than one minute.

 

Looks like you need to take Mike's LS3 advise here, but in my opinion I would be leaning towards the check valve.
I think if any injector was leaking that quickly, the next time you try to start the engine it could lock up with all that gas in a cylinder.
I would still recommend checking the injectors though.
That would be the easier fix, for sure.

 

Is this a job to do on the garage floor. I've had the IRS and transmission out of the cobra but haven't had the vet long enought to even know how to jack it up yet. Dealer wants 1200 labor and 600 for the pump.

 

Here's a how to link.
https://www.corvetteforum.com/forums...fuel-pump.html

 

WADR, if you want to figure out whether you specifically can do the work on the fuel tank, pump, etc., do an advanced search, limit to C6 Tech, add key words fuel pump, etc. You will come up w. at least two threads with pics and full details, one of which will be by Motorhead-47. There ya go.

 

I have an automatic car so I don't know how hard it will be until I get into it. This is a good write up and it looks doable. 1200 bucks I think I will give it a try.

 

Sounds like a bad check valve, but I would still do the fuel injector leak down test just to eliminate them.

Also, shut the engine off in the garage and try to listen for fuel returning back to the tank. It would probably be easier to hear, if the fuel tank was at around 1/4 tank. This would further confirm a bad check valve.

 

I have a manual and I just press the start button, at the top, without engaging the clutch. The car will not start (neutral safety switch) unless I push down on the clutch pedal. By not engaging the clutch, I allow the fuel pump to bring up fuel pressure at the fuel rail.

I do not have an auto, maybe someone can confirm. I assume you must press down the brake pedal to start? If so, do not press down on the brake pedal, but press the top of the start button for a few seconds. Then try to start the car normally. If the car starts up fine, then a bad check valve is suspect. Still do the leak down test. Sometimes we chase multiple issues and this will at least eliminate one.

 

Mine won't do anything when you push the start button. Screen said press brake. I left the pressure gauge on the rail and nothing turned the pump on. Feeling sure it's the check valve.

 

So I'm reading about people having to replace fuel pumps ever few years. If I'm buying one which brand should I buy. Dealer wants 550.00 and I see them on the net for 300. Don't want to do this twice.

 

I would only buy the oem Delphi pump, but I would check Amazon for it...

 

And....get a quote from CULTRAG as well.

Good luck with this major PITA.