Dragon Fire VP44 starts

[CUMMINS_power31]

Having hard starts. If the truck sits overnight or for more than 15-20min or so it will start hard. But If I bump the starter to kick the airdog on wait for it to run a bit then it starts up perfect everytime. Would this be a problem with my lift pump? Am I so post to have fuel pressure when I just turn the key to start? I can hear the airdog kick in for a second when I turn the key but It reads 1psi when I go to start but if i bump the starter like said before if obviously jumps up to 21psi then fires right up. Only way it starts normal is if I drive it go in somewhere come out it in less than 15-20min or so then it fires right up. I did do a search but most people have the opposite problem that it starts hard when its warm didnt see anyone with this problem. Maybe just hard starting of a modified VP? II says no hard starts on their web with this pump. lol Thanks in advance

 

[12vriviera]

there is an anti drain in the vp, there might be one in the the lift pump too, I haven't checked yet on that though, its stuck open letting pressure drain off..

 

[D-LUX]

There is an anti drain in the airdog I would check it first because mine had an issue with hard starts and it fixed it. to check it pull the pump, the filters and the motor, the drainback ball is in the pump base under the electric motor.

 

[ctdiesel99]

or you could be lazy and do what i did and hardwire the airdog to a key on hot fuse like power windows or locks. airdog will stay running as soon as you turn the key to the on position.

 

[smoken02]

The Airdog running while cranking the engine could create a hard start situation also. It could be the over flow valve (OFV). That would be the banjo bolt mounting the return line to the vp. The check valve inside it may be bad.