Not Fair

I have less than 5000 miles on 2011 GS and already have replaced both fuel pumps. Car was hard to start and dealer replaced a weak fuel pump. Thought this was end of my problems. After a short time and a few miles problem started again. The other fuel pump was replaced. Thought my problems was solved. Now car is worse than it was in beginning. Has anyone had this kind of problem with their vette.

EVRose

What are the symptoms? What is it doing or not doing? If its fuel related I would check the fuel pump relay first.
And as far as I know there is only one fuel pump not two.

Not Fair

You can let car sit over nite and it will be hard to start next day. I was told both times that fuel pump was weak and needed replacement. After replacing it would start normal for a few weeks and then hard to start again, just like nothing had been done. After two fuel pumps it is doing it again.

Patsgarage

What exactly do you mean by hard to start ? Does it turn over normally and just not catch ? Or does it cough and sputter before starting ? Once it does start does it idle smoothly and take fuel with no stumbles ? Under load does the engine stumble ? First thing to do is check the fuel pressure when cranking and then when the car is running. I am not sure what the normal PSI is, but I am sure someone here will chime in with that info. Good luck.

jwd

Sounds like a weak battery, based on the description. Are you using a maintainer? Has the battery ever been allowed to drain?

Have you had the battery tested? The alternator?

Not Fair

When I say Hard to Start----Car will turn over normal but does not start immediately. it should start as soon as you push button. This car will keep turning over for about 5 or more seconds before it ever starts. When it was repaired before, both times GM told me it had a weak fuel pump.

Patsgarage

The first thing I would do is check the fuel pressure at rest (before starting) and then when cranking. The system may be leaking down overnight and taking a few seconds to come back up to spec when cranking. On older FI cars you could cycle the key a few times to prime the system, not sure how you would do this on a pushbutton start though.

Not Fair

Its not a battery problem. It has no problem turning over only takes a few seconds to actually start.
Has anyone ever had problems like this?
Very discouraging.

jwd

Perhaps some fuel turned bad? Has the car / fuel sat for a while?

Maybe siphon it out, and put in a full tank with some fuel system treatment?

Classic-Chevy-Guy

Had a similar problem on my C5. Patsgarage nailed it. There was a slight pressure leak from a defective O-ring (I believe) in one of the gas tanks. The fuel pressure would be lower when started the next day.

The dealer found it by attaching a fuel pressure gauge at the end of the day and the next morning the fuel pressure was much less.

Thought he told me he used some smoke device to determine the source of the pressure leak.

Not Fair

I have appointment to take car in for diagnostics. Hopefully they will find problem this time. Could it be its just defective parts? Two separate times they have changed fuel pumps. It is acting like it could be fuel pump again. Is this possible? Can't find anyone else that has had this problem with their vette.

Classic-Chevy-Guy

If your problem is starting when engine is cold (morning), See #10. I would recommend a leak down test overnight to see if there is a fuel pressure leak.

Not Fair

Thanks for everyone's help.

KnightmareCS

Clogged fuel filter?

saplumr

The first place you better look is the fuel pump relay fuse block!

DSOMC6

It's very common issue on the C6 of having a poor connection at the fuse block causing an intermittent short. This results in what appears to be fp failure.

Simply use a jumper wire to power the fp just after the fuse block(when it fails to start) and see if it fires right up.

I've said it before, these fuel pumps rarely fail. My guess is the tech failed to diagnose the issue correctly which is very common unfortunately.

ardalan

Thanks for posting, I have a simmilar issue on my 2010 base-coupe and the dealer said it's a weak fule pump and quoted me $1900 so I have not taken it in yet, but I was skeptical at why a fuel would fail.
My car starts normal about 50 % of the time regardless of it being or hot or cold.
Can you please explain the fuse box, did you mean to bypass the fuse altogether ?
is that hard to do ?
thanks

FortMorganAl

Well, there's the start of your problem. There is only one electric fuel pump. Fuel is transfered from the right tank to the left by a venturi "pump" which is just one pipe inside another and can't really fail and, if it did the only result would be that the car would not run at all because the left tank would run dry while there was still fuel in the right tank.

So let's assume that the dealer replaced the same electric fuel pump in the left tank twice. That would indicate a dealer that was more interested in doing warranty work than solving problems. A faulty fuel pump will cause more issues than just hard starting. If it is hard to start it will also start cutting out under WOT. IF there is any fuel problem at start up it would most likely be the check valve in the fuel line. There is a check valve between the fuel pump and the fuel filter (W on the second page - http://www.hessh.de/Corvette/FuelTankSystem.pdf ). That prevents fuel from draining back into the tank when the engine is stopped. You should maintain 51 PSI at the fuel rails for at least 5 minutes after the engine stops. A leaky fuel pressure regulator ( V ) or Secondary pressure regulator in the right tank (G) could cause fuel pressure to leak down. The procedures to check all of the components in the fuel system as well as all of the other things that can produce hard starting are in the service manual. It doesn't sound like the dealer has much interest in reading those procedures if all they have done is the very expensive task of replacing the same pump twice.

myfunz

This was my thoughts too, has it ever been replaced?

Fred H

I have a 2008 C6 automatic with intermittent starting issues. In park when hit start button, click and dash lights go out. When lights come back on push accessory get in neutral, push start button and it starts. Someone said it is the neutral safety switch? Anyone have an idea how to solve the problem?