my 92 chev 1500 on propane just died on me. no sputtering like when it runs short on fuel. just nothing . we have spark?

Remove the suction hose going to the mixer and push the primer button with the key on and engine cranking. If theres fuel coming out then the problem is in mixer or after (or some other trouble) If there is no fuel present then problem is upstream (before converter) and the fuel lock-off should be checked out.

If it's electric then test for power at post using body of lockoff for the ground, if it is vac operated then apply vac to it to see if it turns on.