Won't Start First Try

[sd455hota]

Hi,

 

I'm new to the forum and have a question. I have an 04 pickup 4x4 2500 with the 8.1 and allison. When I first get in and turn the key it cranks for a few seconds, won't start and stops cranking. I try again and it starts right up. During the first try it actually cranks the few seconds on it's own even if I let off the key after the first couple seconds. The truck runs fine and has no other issues. No engine light etc.

 

Any thoughts are greatly appreciated

[whizbanger1]

Had a similar issue, turned out to be a loose battery cable.

[Silverado4x4]

Fuel pump is on its way out and is weak, first crank builds pressure and second crank theres pressure so engine starts. As far as the releasing the key during crank, all newer GM trucks and cars will do this, all you do is bump the key to the start postion and the engine will crank till started, you dont have to hold the key while cranking.