Destroyed a 7.3 - can't get to run with new motor now :(

[schoen311]

Blew out both sides of the block when a powder metal rod came apart in the bottom end.

Bought new long block and put the motor together. New innercooler, new 38R Garrett, high pressure oil pump & IPR both changed twice, cam position sensor changed out 3 times.

PROBLEM: When starting, will crank over and over, won't start. Crank over again, will fire then die. 3rd time's the charm, will start and run. Sometimes it'l fire and die the first time, then run fine. Sometimes, it won't start at all and when you look in the hpop reservoir, it's EMPTY! If you manually fill it, it will start right back up.

When cranking and it won't fire, the gauge on the dash doesn't move at all. Once it starts, the needle will move. My other 7.3l - the needle starts to move as it's cranking over.

QUESTIONS:

1. Does the low pressure oil sending unit have anything to do with it not wanting to start?
2. If the low pressure sending unit doesn't sense low pressure, would this cause it to die after firing?

Stumped and frustrated!!! Love the truck, but ready to light a match and buy a Chevy!

HELLPPP!!!

Tammy

[HVAC SuperTech]

ok, the LPOP(low pressure oil pump) is attached to the crank. it should turn as the engine is spinning over. If you are not getting oil into the resivior on your HPOP, then you probably arent moving oil through the block. I would start there. Was the engine a reman? or did you put it together yourself? I would look towards the pump or the pickup in the pan first.

[schoen311]

Engine was a new longblock, put together by us (hubby is a shop teacher and experienced mechanic). We've already replace the low pressure pump once thinking along those same lines, but didn't work. Didn't think about the pickup in the pan though - will take a look at that.

The weird thing is, we'll do something like change out the HPOP, and it'll seem to work for 3-4 days - runs fine. THen will begin this starting and dying thing again - inconsistent.

Any chance it could be some sort of relay or sensor that's intermittent?