Your ICP voltage and PSI are too low to start the engine. See the comparison chart in the link below.

https://www.ford-trucks.com/forums/1...l#post18353142

I would be looking closely at the ICP and harness. Unplug the ICP, take readings. If the ICP does not default to 750 psi, look at the wires all the way into the loom.

Use a multimeter to see if you are getting 5v reference at the ICP connector.

 

ICP defaults to 2200psi when its unplugged.

 

Is there oil in the pan? Is there oil in the HPOP reservoir?

I wouldn't suspect the GP's or GPR because it looks like you replaced the GP's and even if the GPR is bad, they are not really needed in ambient temperatures 65 degrees or more. They still come on at this temperature, but they are not required.

How is your fuel pressure? You said a bit if white smoke, so I would not suspect fuel, but it is worth looking into.

https://www.ford-trucks.com/forums/a...4&d=1592859516

As for testing the HPOP, there are not many options.

https://www.ford-trucks.com/forums/1...l#post18608442

 

Yes, there was oil in the reservoir. In been drained and refilled with oil. Oil is also topped off.

I dont have a fuel pressure kit to test the fuel, but when I changed out the fuel filter and primed it the bowl was full again with fuel.

At this point, I'm going to have someone with with the proper equipment to test out the HPOP. Getting expensive throwing parts at it and not coming up with a solution. I've even bought a IDM off a truck that was running before but have yet put it in. Kinda my last resort.

 

being that your icp is defaulting to 2200 psi means something electrical as sous mentioned. There was someone else that had the same problem recently and I believe he changed out the icp pigtail and started seeing actual numbers.. you should be able to watch the icp climb. Wish we could be more help to you, please let us know what you find out

 

This may be the FTE'r Jstihl is referring to.

https://www.ford-trucks.com/forums/1...l#post19380943

 

Del, let us know how much cranking you did after you replaced your injector orings. Did you open the hpo rail and crank until oil flowed from them?
One way to test your hpop is to remove one hpo line from lets say the passenger head. Have someone crank the motor while you direct that line in a jug. Make sure they can see and understand your stop signal...hahahha "safe word". How much comes out? Should be alot. Mine dribbled when my pump went bad.

 

I hate it when ppl never come back and post the end result. I have been slowly but surely working this truck back to decent performance.

for a few dollars, I just ordered and replaced the ICP. I don’t know if I got a bad one new out of the box or what and don’t intend to find out. Threw the other one in the trash. Not worth it.

I removed every injector and checked the shim Thickness for every Poppet - they were terrible. I mean I couldn’t get .002 in any one poppet. Ordered shims, shimmed all of the and it starts wi 3-4 cranks. Kudos for the mfer who figured that shim idea out!

look forward to cooler temps to see if it holds and allows continued starts cold. Never really figured out the readings issue. Alternator is strong. Went ahead and got new batteries.

if you are having hard times w starts and injectors firing even when it’s 80-90 degrees - stiction is real and it can be hell on starts at any temp. When I pulled the poppets off - I had to slide them off the injectors bc the oil had such a hold on them to the base plate of the injector. It wasn’t going to start wo some of starting fluid and that’s no way to go.