ThatWhiteVette

Hey all,

I recently purchased a 2013 grand sport manual with an A&A supercharger kit... The car has injectors and a Kenne Bell boost a pump that were optional for the A&A kit. The last couple of weeks I have noticed that when I have a half tank or less it will cut out at high RPMs. If I fill the tank up and it's above half tank it runs perfect... Any ideas on what could be going on? I am very new to Corvettes. Any info or suggestions would be greatly appreciated! Thanks in advance

- Dillon

smoothisfast

There are 2 tanks, one on each side of the car. Could be a problem with how the fuel transfers back after a full fill. Here's a link to some members with more experience than I. Good luck!

http://www.corvetteforum.com/forums/...ks-or-one.html

0Anthony @ LGMotorsports

I would try and get as much info as you can. Get a fuel pressure gage on the car and see if it is loosing pressure or not.

Hook up to the computer and see if something doesn't look right in the sensor feed back when the car does it.

Could be a crack in the hose from the pump to the top of the tank, and when it is full it can get gas through but possibly if the crack is exposed it might be bleeding off. Fuel leak inside the tank itself....

schpenxel

You'll usually get codes if the transfer system isn't working correctly. It's pretty particular about expecting the fuel level to drop on the passenger tank first, then driver tank

I'd agree with LG though.. need to log what's going on (including fuel pressure) while it's happening first

EnginerdX

I had the same thing going on with a different car several years ago and it wound up being the fuel pump. Do you have any way to check/log your fuel pressure at the rail?

Grimlock13

All I can add is if it is the fuel pump itself or you have to drop the tank(s) anyways you might as well put in a Z06 pump.

Chiselchst

Both LS3 and LS7 fuel pump PN's indicate the same on the few sites I checked. Is the Z06 pump really different? I've read at about 2011/12 the LS3 got the Z06 pump?
How many miles on your car?

GS_DAN

It has not been proven that ANY LS3 cars came equipped with the LS7 fuel pump.

The replacement part number is for an LS7 Fuel pump for all years of C6s

ThatWhiteVette

Hey all, thanks for the input and suggestions.. Haven't been able to log the car really, but I found that the fuel level has nothing to do with it. Yesterday I watched the voltage drop from 14.3 down to 12.9 when the car cuts out at 5500rpm... Bad alternator? (Had it tested at auto zone and the results were fine... but it only test up to 2000rpms and my issue is when the car is hot and at 5500rpm) Should I be looking for a bad ground maybe? Or still bad ALT?

Seadawg

Mine personally came with the LS7 fuel pump, because I personally saw the part numbers when the dealer swapped out the bad fuel sensor under warranty. I have a 2011 GS, see the addl. info in my profile.

I was going to pay the extra and have them swap the pump while they were doing it, but did not need to.

I posted all of the info (part numbers, pics, etc.) in another thread out here.

ThatWhiteVette

bump, only cuts out when car is hot and coolant temps are around 200-205 and at 5500rpm WOT.... Voltage drops from 14.2 down to low 12's on the DIC maybe even lower than that. When car is running correctly the voltage will not drop any lower than 13.7

C6topless

I think you are correct in your assumption you may have a bad alternator ... I have seen what you described several times and traced the issue to the alternator . What I would do is take your corvette to a shop that specializes in alternators ... and have them load test your alternator while it is hot.

Colleptic Corvette

I am having this exact problem. I have to drive the car for at least 30min, then at WOT it starts to hesitate, hold the RPM and eventually feels like it is cutting fuel. It could be so many things, but I am super curious to go back out and look at my voltage...the problem goes away if I shut the car off and let it cool down...hmmmm

C6topless

I almost forgot -- if the alternator checks out, check your battery terminals ... for some strange reason, I have found the negative terminal loose quite a lot on the C6.

schpenxel

The cable end GM uses on these cars is pretty crappy. Way too lightweight IMO, so that doesn't surprise me.

c6moneypit

I had this exact same problem. Running same setup. After the car was warm and fuel below half, i noticed my fuel pressure guage would drop below 45 psi. If car was cold and half tank or less it was fine. If i added gas when it was hot it was fine. Turned out the hot fuel and fuel pump combination caused the in tank fuel pump to become very inefficient when under boost and the boost a pump was trying to spin the fuel pump faster. When i added cold fuel from a gas pump, seems that helped cool things off and the pump would work fine with the boost a pump. My solution was to use the secondary external fuel pump system from a&a. It bypasses the in tank pump at a set boost (mine is set to 3 psi). So when cruising around my in tank fuel pump is in use. Once i hit 3 psi and stay on the boost, the externaly secondary pump system kicks in to ensure a steady fuel supply. This setup has worked perfectly, i always have minimum 55 psi fuel pressure, even during summer HPDE track events. Might be worth it to research this possibility.

Mike's LS3

Four months after my A&A kit install, my fuel pump in my 2008 with 62k miles crapped out. I also have a BAP. I probably did not help it any going into boost with less than 1/4 tank. Since then, I had a Z06 fuel pump and never go into boost with less than a quarter tank of gas. It's been 1.5 years with no issues and a solid 58 psi fuel pressure at WOT.
If this did not work, I would of gone with A&A's secondary fuel pump like you did.

c6moneypit

That was my other option but i wasn't sure if the in tank heat would have still been a factor with the z06 pump. Plus we weren't thrilled about dropping the fuel tank. I'm glad to hear that the z06 pump fixed the issue as well... i always wondered if that would have worked as well.