I installed a ProCharger system on my car (2005 C6), and I bought a new Z06 fuel pump instead of going with a BAP. I left the stock injectors in, because I do not have a tune for it yet. The car has only been started to check everything over; it has not been driven. I just got around to installing the Z06 pump today. Prior to installing it, my old stock C6 pump ran at 60PSI, and after installing the new Z06 pump, it was only at 40PSI. Also, after turning the ignition on and letting the pump prime, it would read 40PSI and go down to 0 immediately. The car also had problems starting, like it was lacking fuel. I know it's not the gauge, because I have used more than one gauge, and it has read the same...40PSI. I was wondering if it could possibly be a defective fuel pump??? ANY help would be greatly appreciated!!!

 

The pressure of the new pump should be the same as your old one. The volume is the difference. If you are at 40PSI, something is restricting the flow or the pump is defective.

Elmer

 

Yeah, I can't think of anything that would be restricting the flow, because it was fine hours prior to installing the new pump. The thing that leads me to believe it's a defective pump is that when it primes, it will read 40PSI, then drop down to 0. It should stay at 40PSI (well actually 60PSI).

 

Your problem is in all likelihood the connection of the forward and return fuel lines located inside the crossover tube at the driver's side tank. If you managed to lose one of the plastic ferrels or or lose one of the o-rings, you'll have decreased pressure when engine is running and fuel pressure will bleed off nearly immediately upon shutdown.

 

To help you understand what might be wrong you need to have a complete understanding of how your fuel system functions. The link below takes you to a very good write-up. Although it was written for a 2004 car, the functionality and hardware are the same in the C6 cars. Pay particular attention to the description of how the fuel transfer function works.

http://www.corvetteactioncenter.com/...el+Tank+System

I put together a write-up on how to R&R the pump a while bank...link is below. You have already “been there done that” but there are several pretty good photos that show the O-rings in that crossover tube. The one that in all likelihood is screwed up is the top one. If you do not have a tight seal here whether it be because the O-ring fell out, the ferrell fell out or you perhaps pinched the O-ring, this connection must be solid as it is one of the two lines that carries 60psi. This one goes over to the passenger side tank and supports the fuel transfer function. The other 60psi line goes to the fuel rail up front. If you have a bad connection inside the upper of those two connections inside the crossover tube you’ll never get 60psi. It will also bleed down almost immediately when you shut down. Another side effect of this problem is that your fuel transfer function will not work…requires greater than 50psi in that upper crossover tube for the fuel transfer function to work.

http://forums.corvetteforum.com/c6-t...fuel-pump.html

 

THANK YOU!!!! Believe it or not, I actually used your write up to do the entire install. It's bookmarked in my favorites, lol. EXCELLENT write btw!! I was worried that may be the problem, because when I was reconnecting the coupler, it wasn't turning clockwise very easily. I also took a picture of the inside of the cross-over tube after pulling the tank, just to get a good idea of what it looked like. Here is exactly what it looked light RIGHT after pulling the tank...



It had an o-ring on the top line, but nothing on the bottom. Right before I was re-installing the tank, my dad found a yellow o-ring on the ground, and I figured it was from the top line since it was on in the picture. He said he couldn't feel an o-ring on the top line anymore, so he put it on the top one. Maybe there was already one on the top line, and the bottom o-ring was the one that had fallen on the ground???

 

There SHOULD NOT be an O-ring on the crossover tube side. That O-ring belongs in the connector for the two lines inside the tank. When looking in the end of the white nylon fitting on the top of the tank there should be a single O-ring and then a small black plastic ferrel in front of the O-ring on both the upper and the lower lines. Both the O-rings and the ferrels must be there or it won't work properly.



Not a very good photo (hard to get to) but you can see there are no green/yellow O-rings in there

 

I thought that it was very odd that only one O-ring would be on the crossover tube side. However, I checked for O-rings on the tank, and it looked like the ones in the picture you posted. Is there a white/yellowish plastic piece behind the O-ring that I could have mistaken for the actual O-ring? For example, in this order... [black plastic ferrel first][O-ring middle][White/yellowish plastic last]

 

To be honest....I simply do not recall there being anything behind the O-ring...but there could be.

Maybe someone else who has done this more than me can chime in?

Maybe PM member "VETTE PHASE" ... some of the pictures I used were his.

 

I'll drop the tank and look at it again. I am also going to install new O-rings just in case the old ones are damaged. So I will look to see if there is anything behind them. Thanks a bunch for your help! I was pretty much devastated after doing all of that work and things not turning out right, lol. This definitely sounds like the problem though. Good news is....I am going to be quicker at removing the tank, hahaha.

 

How do you think I have a pretty good idea what your problem is?....been there...done that!

Good luck...it is a lot easier the second time because you know what to expect. Be sure to lube up all of those O-rings before you slip things back together...it helps. Also, dropping the 5 bolts under the passenger side tank will give you a little more play when you go to disconnect that crossover tube on the driver's side.

 

Yep, did all of that the first time around, lol.

I figured out the problem though! When the driver's side tank was disconnected from the crossover tube, the ferrel from the top line pulled out and stuck on the line in crossover tube. So in this picture, the o-ring AND ferrel are still attached to the line inside the crossover tube:


After dropping the tank, I found a severely damaged o-ring, lol, which doesn't surprise me at all now. Then I checked the lines inside the TANK, because I knew that I saw something that resembled an o-ring on the top line before putting it back together the first time. And this is what I saw (note: I had already removed the bottom ferrel and o-ring) :

So I removed it, and it was a plastic ring. This is what it looks like:


Here's a picture with it in reference to the ferrel for the top line:


THEN...behind that plastic ring was ANOTHER o-ring (green):



Has anyone ever seen this??? So it was plastic ferrel, yellow o-ring, plastic ring, then green o-ring.

 

Also, I went to the dealership to order new o-rings, and they could only find the large o-rings. Does anyone know where I can get the smaller o-rings??? Btw, the o-ring for the top line is smaller then the o-ring for the bottom line.

 

where can I buy crossover tube o rings?

 

looking for crossover tube o rings. Where can I buy them?