I just replaced my old 7.3 psd engine with a used one with 118,000 miles, I attempted to start the engine before connecting the alternator ,radiator ect. The engine spins over fine but will not fire. I noticed the dash oil pressure gauge was,nt moving so i checked the HPOP reservior it was empty, refilled it and and the gauge move up to normal "engine still did,nt crank. rechecked the HPOP reservior it was bone dry again ,refilled 3 times and pressure gauge never moved again nor would the engine fire up. I replaced the crank sensor still no start.

This is a list of the things i left off , only cause i wanted to make sure the engine was a good one before finishing up. air meter box,inner cooler tubes, radiator,transmisssion lines,alternator, and entire serpentine belt assembly.
Would any of this cause the engine not to crank?
I have a brand new HPOP on my old engine but i have never changed one, could this be my problem? Are they hard to change?

I know this is alot to digest but i,m trying to be detailed as possible.....Thanks for any help in avance....Tony

 

So right now, there isn't any coolant in the engine and no serpentine belt??

 

correct!!

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Changed the HPOP today, refilled the reservior and she fired right up. I let it run for about 2minutes then shut it down. Now it,s time to install the radiator and other stuff, THEN GIVE HER A TEST DRIVE.....I learned alot by doing this engine swap myself. These 7.3 psd are a peace of cake to work on...Tony

 

yup.