91 astro died - wont start - electrical?

hi all,
i have spark and fuel, spark may be weak, fuel seems strong being injected in spurts
timing seems as if it could be off, firing / detonation in exhaust, but it will not start
checked ignition module - ok - thanks autozone for the free check
fit hei distributor, fires up first swing, but dies as no fuel - but thats just as the hei does not talk to the rest of the electrical system

so i am presuming i have a weak spark - coil - but if that is so why does it seem to have timing that is off?
is there a crank position sensor on these old motors? if so where and could it be that?
what else could it be??

If the engine has high mileage, it could possibly one of these:

Engine timing chain has broken
The Ignition module located inside the Distributor is bad
Ignition Coil is bad
Faulty fuel pump (not enough fuel to start engine)

Last resort--take the vehicle to the GM dealership and have them locate the problem... good luck