DON'T GIVE UP YET
I think i may have found your problem....."overflow valve"
the overflow valve is located on the side of the injection pump. it is also used to connect the fuel return line(banjo fitting) to the fuel injection pump.

fuel volume from the fuel transfer pump will always provide more fuel than the fuel injection pump requires. The overflow valve is used to route excess fuel through the fuel return line and back to the fuel tank. Approximately 70% of suplied fuel is returned to the fuel tank. The valve opens at approximately 14psi. If the check valve within the assembly is sticking open, fuel drainage of the injection pump could cause hard starting.

i would think the longer it sets the harder it would be to start because all the fuel is drained out of the IP.....

no codes will show if it's stuck in the open position. but will cause a hard start condition........ the check valve is the front fitting of the two on the side of the injection pump, i had mine replaced when my IP was changed.
I HOPE THIS HELPS....JOHN

 

The IP came with a new overflow valve. I have checked it and the spring moves back and forth. As far as I know it's working properly. Thanks for the tip though.

 

i would still check it, the procedure is : remove valve from IP, set regulated air pressure to approximately 14 psi.
using blow gun , apply air pressure to valve inlet, internal check valve should release and air should pass thru valve,if not replace valve.....

reduce regulated air pressure to 10 psi and observe valve. valve should stay shut. if not, replace valve

 

I don't have the equipment to do a test like that. It's going to have to go to a shop. I'd hate to say it......

I took it for a ~50 mile drive today and it has been starting up ever since. Maybe I got all the air out or the leak sealed itself? Probably not, but wishful thinking is all I have left at this point. :P

 

Nope, took a couple times to start it this last time. The longer it sits, the harder it is to start. I don't know where this magical leak could be, but it's kicking my ***.

 

Put a piece of clear tubing between the fuel filter and the vp44. If it has an air leak it will have bubbles in the clear tubing. If there are no bubbles it must be electrical.

 

Hmmm....not a bad idea. I might put a piece of clear tubing on the return line, too. I'd like to know where all my fuel is going.

On my little road trip the readout was telling me I was getting about 19mpg on the highway today.

 

if you can't test it then replace it, it can't cost that much .... the place you bought the IP should have some

 

They wanted $50 if I didn't send my old one back. I suppose I could order a new one.....

I put a clamp on the return line after I shut it down to see if it would stop the loss of prime, but it did not. I'm thinking the return line isn't the problem after that.

 

i can't think of any other place you could be losing prime, (if that's what's happening) unless you got a bad VP44.... also, did you check fuel at the injector lines at the head after setting a while?

by the way ,where are you located?

 

I'm wondering if the injectors are what's causing this? Could they be leaking all of the pressure into the cylinders causing the system to lose prime?
I'm scared to crack the injector lines after it's been sitting because it might take 3 weeks to get it started again.

I'm located in Lake Havasu, AZ.

 

not very likely the injectors with the mileage you have. in fact I've never heard of it.... the only way to find out if you're losing prime is to crack the inj lines. if you don't have fuel at that point, it's going some where.... if it absolutely won't start, disconnect the grid heater cables and tape them securely so they don't short out and try to start giving a shot of starting fluid...let me know the results.......... john

 

I had an air leak in my system, I could watch the bubbles in the clear line I ran. My truck still started every time. I think you are barking up the wrong tree here. A scan tool would really help a lot to diagnose this. You need to look at the data stream and see what you are missing. A digital volt ohm meter would work too, it just would be more time consuming. I am thinking that the crank sensor may be failing when it is hot.

 

How about WD40? I don't think I have any starting fluid. Last time I cracked the lines to check all the connections there wasn't ANY fuel in the lines. Maybe a few drops here and there, but there wasn't ANY pressure in the lines.

 

I've heard of using WD40 but have never used it... are you saying no fuel at the loosened connection while cranking?