Here comes the first of many dump questions. Is the HPOP reservoir connected to the engine old system? Does it use the same weight oil?
no question is dumb, yes it is the same oil as the oil in your crank. the reservoir is fed by the low pressure oil pump that sucks oil out of you oil pan. your HPOP is a high pressure low volume
pump......or the stock ones are. this is why the low pressure oil pump can keep up with it.
this is why it is so important to use good oil and change it often a heui system. cumming and duramax not so much.
as for your cold start problem. when you get a scan tool hooked up take the truck out on the highway after its warmed up. get up to about 60mph and floor it to about 80mpg at least. wile your doing this have your scan tool with you and look at the ICP
PSI. when you floor if it will spike to somewhere around 3000psi +/- and then drop and should level out and stay at around some number in the 2000psi range. mine leveled out at about 2750psi, and that really good for an old 15*. i think 2500psi and above is good. 2100psi is alright, not really that good. and below that i might replace the hpop.
that is how you test your hpop. at wot
as for crank test for your hpop. turn your key on and look at the ICP psi, then crank. it takes about 400psi to start a 7.3 let us know what your get.
you know that the wait to start light is just and idiot light right? when it goes off your glow plugs are still being powered more than likely. i think they stay on for at least 120 seconds, i think. so what im saying is when the light goes off dont crank, wait another 20-40 second and then crank. see what happens.
also the stock GPR are 100% gunk if you ask me. they dont last and when they work they sometimes dont work 100%. i would recommend a stancor of wester snow plow realay. look them up on here and see what your think.