Lack of one of the following:

Correct amount of Fuel
Correctly timed and sufficient Spark
Adequate compression

Now that we have that out of the way, if you search the site, you likely find a litany of items to check to verify each of the above items.

Personally, with the limited information you gave to go on, I would say these are the most likely causes:

Fuel Pump Relay
25 amp fuse (if so equipped)
Ignition amplifier
CPS
RSR (if so equipped)

All of the above have been covered in depth so simple searches will give you a number of things to check. Have you pulled the codes?

Mike