Archived truck runs rough

[LPenton]

I have a 99 3500 yesterday the truck ran good i stopped and shut it off I tried to start it and it wouldn't crank. I bled the lines to the injector pump getting plenty of fuel I cracked the injector lines and cranked till i got fuel still wouldn't crank I disconnected the battery for 10 min. cracked the lines again finally it cranked but runs real rough I tried cracking injectors open one at a time while running still runs bad barely smokes tried cracking return line open while running still runs bad got plenty of fuel to return line replaced LP 4 months ago

 

[bmoeller]

Originally posted by LPenton

I tried to start it and it wouldn't crank. I bled the lines to the injector pump getting plenty of fuel

Why did you crack the fuel lines if it wouldn't crank? Two completely different systems. Which problem is it, not cranking over?



If you cracked the lines and it was running rough, how long did you let it run? Sounds like you now have air in the fuel system.

 

[MidwestMotorman]

I think he is just using his terms wrong. I think he is saying cranking instead of firing.

The lift pump is a great tool in bleeding, but the VP44 does some on its own via returning fuel. You just crack open a brass plug on top of the fuel canister to bleed the air. If you have enough fuel to the injectors to where it is firing, the air should clear out after a little bit.

Maybe your VP44 injector pump is going bad, but they usually completely die. Drain some fuel out of the fuel filter canister (using the drain lever) and check it for water. You could also check it for slime which may be growing in your tank.



You should have thrown a code when it didn't start the first time. That would be the best place to start before you attempt any more self help. You may have had a sensor go bad and the truck will run bad no matter how many times you bleed things.

 

[LPenton]

the reason i cracked the fuel lines is because the truck would turn over fine it would not start It seemed like the same problem i had four months ago when the LP died. no water in fuel filter is clean. I let the truck run for about 20 min. still running rough. what do you mean by throw a code.

 

[Missouri Mule]

If it is electrical/electronic problem the pcm should have a code stored in it. You can turn your key on and off twice in 5 seconds then leave it on the third time ( if you have service manual it has directions on how to do it) or use a scanner to get code from pcm.