have you checked for codes?

key on and off 3 times and on the 3rd one leave the key on and see it you get any codes on the OD window

crack the fuel line at the injector pump bump the starter to start the Lift pump and see it you have fuel ..if you do then crack at least 2 line loose at the injectors....if you have fuel then the VP should be ok

on the VP there is a return line with a check valve....make sure thats ok.


keep us posted

Scott

 

make sure you don't have a pin hole air leak, the conditions you're describing sure sounds like the fuel is draining back into the tank. sometimes you can get air into the system without seeing a fuel leak

 

Thanks for your help guys.

Is there an easy way (idiot proof :rof)to check if I am getting air in the system?

 

Thanks for your help guys.

Is there an easy way (idiot proof :rof)to check if I am getting air in the system?

Take the fuel cap off and put about 1-2 PSI of air pressure in the fuel tank... The leak will be peeing on the ground for sure...

 

Just for fun try running it with the fuel cap loose, a bad cap can and will allow the vacuum in the tank to draw the fuel out of the IP and the filter, also read in the factory repair manual that a faulty relief valve (on the IP) will cause hard starting as well(it allows fuel drain back too)

 

Just for fun try running it with the fuel cap loose, a bad cap can and will allow the vacuum in the tank to draw the fuel out of the IP and the filter

OK, wow what a difference taking the cap off made. I run it for a minute with it off (just before shutting it off) and then later in the day, or in the morning, it fires right up....no bumping needed.

Seems to fire quicker with more fuel, so now the combination of a full tank and no cap leads to easy starting.

You guys still thinking air leak?

I will try pressurising the tank.

Thanks for the help so far. :thumbsup

 

my o2 has a one way valve on pickup tube, might have trash stuck on it, fuel runs back in tank. It is in bottom of tank.
Truck had a feed pump mounted on engine.
Now beside fuel tank.

 

you have an air leak...
I had the same problem the o-rings between the injector hard line and injectors where bad..
I would look for an air leak

 

Replace your fuel cap, it has a faulty vacuum valve, when fuel is drawn out of the tank air cant get in, all fuel caps have a vacuum and pressure relief valve. the dodge tank also has a vent on the sending unit as well , it could be plugged up with dirt.
pressurizing the tank will help you find any small air leaks. I think if you replace the cap all will be good
BTW leave it loose not off all together

 

It does do that whoosh.

I checked the vent, it was blocked with mud. We tried cleaning it, but still get the vacuum.

 

you may want to pull it off and see if it's blocked and blow compressed air from the inside out of that breather vent tube