My 83 - 240 cranks but won't turn over.

Here is what I have checked so far:

Both fuel pumps are working(hear them humming)
Removed return hose from fuel regulator to tank, put in container, cranked engine for 30 seconds-had 28oz of fuel in container
Removed oil filler cap, had someone crank engine- see movement in there- so timing belt is ok.
Removed plug wire and had blue spark when held near engine and cranked.

I am totally confused- have spark and have gas, but no turnover.

Any suggestions?

 

Squirt some starting fluid into the intake and the crank it: if it fires up briefly you'll know you have a fuel problem, or if not, ignition...

 

did you jump fuse terminals to check the pumps or how did you hear the pumps activate?

Ignition on or when cranking?

You have LH2.1 right since you said you have a FPR.....? well you don't have Kjet, my point....

Check:
rubber oring on crank pulley.......will mess with timing and no start...given your year...but you might have a crank pulley without an oring..
25amp fuse by battery are (if any) replace if blown
Hall sensor wires...trace and see if damaged
Alternator solenoid wires...check to see if oily...clean terminals
Temperature sensor connection....clean and re-connect