Hockeyman

iTrader: (4)

Hello all - I need some help diagnosing an issue i'm having with the cobalt.

A few weeks ago, my car began cranking about 3-5 seconds longer than normal. Once it starts up, it runs fine. It does this if the car has been sitting for more than 2 hours.

I would like to start troubleshooting, and my first guess would be the fuel pressure sensor. Am i correct in assuming that if this sensor isn't working properly, pressure is lost at the fuel rail when the car is off? One more thing which makes me think this is my issue, if I turn the car to the on position, and prime the fuel pump, it will start up quickly just like normal. My second guess would be a dirty fuel filter, it hasn't been replaced in about 30k miles.

07 LSJ, 60's, 2.8, supporting mods, 65000 miles.

Any help would be great, thanks in advance!

LS6Rally

iTrader: (14)

i would replace the fuel filter first, as that will never hurt to replace it.

but i would agree that it sounds more like it is loosing residual pressure while off.

Pyros777

iTrader: (4)

Fuel filter for sure based on personal experience. If you let it go on too long you will end up needing a new pump.

ItalianJoe1

iTrader: (10)

The fuel pressure regulator is in the tank, as part of the pump basket assembly. That's where you are having an issue, it's not holding pressure in the line.

I'd suggest a filter anyway because you haven't changed it, but plan on dropping the tank and replacing the regulator.

Hockeyman

iTrader: (4)

Thanks Steve, I remember your pump going out a few years ago right?

Pyros777

iTrader: (4)

Yep, although what Joe posted makes a lot of sense. Guess it would be worthwhile to just swap the filter and see where you stand.

Hockeyman

iTrader: (4)

On another note, i moved into a new apartment about 6 months ago and now garage the cobalt. I notice when I have more than 1/2 tank of gas, my garage reeks of gas when I leave for work in the mornings. Any ideas about that??

BlkWdoSS

iTrader: (7)

Have you gotten the "check gas cap" thing on your DIC? Its possible your Evap system has a leak

Start with the filter Blake, its a cheap and easy way to start. Are you getting any idle surge?

Hockeyman

iTrader: (4)

I've had p0455 for forever, dealer did a smoke test on the evap system a while back and found no leaks. They say there was a recall for 07s for this issue, but it involved a reflash which I refused due to my tune. I do occasionally get the check gas cap message.

ItalianJoe1

iTrader: (10)

The recall is for leaking fuel canisters, which will cause the gas smell. Odds are you have a small leak on the top of the tank. That can cause a loss of pressure when the car sits as well.

Sunburst_SS

there is a special policy for the fuel lines on the fuel pump assembly fracturing....causing a leak
and loss of fuel pressure which would cause your extended cranking issue.

Look under the car and you will probably see some fuel leaking down the back side of the fuel tank.

johnladow07

iTrader: (1)

Im going through the same thing. I saw all the recall stuff, but apparently my VIN isnt one of the cars in the recall. Post back with the fix if you find out. My symptoms are very similar. Gas fumes over night, longer than normal start up, but everything else normal.

Sunburst_SS

check for fuel leaking back of the fuel tank......they had an issue with fuel lines on the pump assembly fracturing.

Chevrolet Cust Svc

Hello johnladow07,

It looks like you're already aware of the open recalls on your vehicle (although I can look into that or warranty information with the last 8 of your VIN) and I can understand if you're looking for a DIY solution to this; if I can look into anything further for you I'm happy to do so.

All the best,
Sarah
GM Customer Service