Truck started to stall. Pulled over and it would start idle a little then die. After a few minutes it would not start at all. I have 40 psi on the fuel rail, new plugs, have spark and pulse. It will idle if i spray starting fluid in the intake. Any suggestions would be great. thanks

Tried starting with throttle depressed dont think its an IAC

Is 40 psi enough?? haynes manual says 50

 

Not enough to give a hint since you say you have everything for the motor to run.
50 lbs fp is to high, 40 is ok.
Just some thinking; is the motor being flooded? Regulator leaking fuel into the intake.
Is there a problem with the air intake tract from the air meter to the throttle body?
Any plugups not fully seated?
Are you sure there is no ignition issue?
Fuse #8 not seated well in a fuse block such as for the fuel pump etc.
Start fluid could fool you into thinking there are no issues with anything just because the motor tries to run.
Somthing is an issue.
Good luck.

 

Sounds like a possibly large vacuum leak. I have also seen an airfilter come apart in these trucks and restrict air flow which caused the problem you have.