Scott Mills

My truck has an occasional problem. After sitting for a couple of hours the truck will have a hard time starting. It will take 3 or 4 times with the key to get it running. When you turn it over the first time it sputters and dies, the second time it sputters, sputters, and dies. Eventually of the 4th try it will start. When you put it in gear and step on the throttle it almost dies unless you feather the throttle a little. When the truck warms up after 5 mins, it runs like normal. Now the odd thing is this problem will happen for a couple of months and them will be fine for a couple of months, but when it comes back it seems to be getting worse. Weather and temp dont seem to be the cause. I suspected a fuel pump issue and replaced my walboro with another new unit, but no solution. My fuel pressure snaps to 62 psi after turning on the key and the pressure remains good when starting. I have timed the pressure drop after turning the truck off and its about 10 psi in 5 minutes. I have some 60lbers that I am waiting to install if its a possibility that the injectors are worn. I really need to get this issue fixed. All truck mods are listed in my sig below.

KySilverado

iTrader: (7)

Mine is cold natured. Does the sputter until it warms up. Always fires up on the first crank though. Sounds to me like tuning... and my first thoughts were fuel pump or FPR but sounds like you eliminated that as an issue.

Stoichiometric

iTrader: (10)

There are some start up flare correction tables that pull timing upon start up to prevent rpm flaring. You could try reducing the amount of timing retard and see if it helps. Look around in the tune for cold engine related tables.

Scott Mills

Well I thought tuning for a while, but with the problem being intermittent I kind of ruled it out. Last night I went out to the truck to do some more trouble shooting after the truck had been sitting all day and it started right up with no problems. It will probably give me problems today though because I don’t have time to look at it.

Scott Mills

No more input?

zippy

Do you have any logs of it when this is happening?

DrX

iTrader: (7)

Sounds like there is some fuel pressure leak-down occurring. Did you replace the flex tube along with the pump? You would need a fuel line shutoff adapter to isolate the leakage to either the injectors or the tank end of the system. The valve goes between the chassis line and the rail. I think that even if the pressure goes straight to 62 at key-on, there may be some air trapped in the line that has to clear if the line has drained back into the tank. Probably more of an issue with returnless systems. A leaking injector could also cause hard starts/misfires.

Scott Mills

I was thinking that air trapped in the lines would cause the hard start, but what about the hesitation after its started? Still air trapped? There was not a flex tube in my tank, it was replaced with a piece of rubber tubing and hose clamps. I guess that I will look at installing the 60 lb'ers I have in the garage and eliminate the injectors as the cause.

DrX

iTrader: (7)

Could take a minute to clear the air from the line. Is that rubber hose SAE J30R10 for intank use?

Scott Mills

I am not sure about the rubber hose, it was installed by TRT last year, but it looks like a regular fuel line type hose.