I've replaced filter, lift pump, all new lines, fss solenoid and truck wont idle it starts right up but only stays running when my foot is on the gas

 

Telling us about your truck will drastically improve the level of help we can give you.

At this point I don't know what year motor / injection pump, so I can not help you.

What lines are new?
Is the fuel tank full of fuel?
Is the FSS working? Just because it is new doesn't mean it works right.

We need some help from you if you want some help from us.

 

Sounds like a P-Pumped truck to me, and also like idle speed adjusted too low.

Can you keep it alive at about 600-700 rpm with the pedal?

If yes adjust idle by applying wide open throttle (engine stopped!), loosen locknut, turn out low idle adjustment screw 1/4 turn and set locknut. Release go pedal and start engine- check for correct idle speed, auto in drive, AC on!




I hope you have a p-pump truck, and I second Oliver's notion that you should give more info about your truck to get the appropriate help.

 

Good info AlpineRAM....but this guy posted a question in the HELP section, then after just a few minutes of it not being answered [at 3 AM no less] has not been back to look for answers about a week later...

If we only could have, not only guessed what his year / style of Cummins motor he is working on, but solved the problem in under 5 minutes...