It takes 5 things to make a motor run: Spark, Squirt, Suck, Squish, and Timing, and these things must be provided in the right amount and in the right order.

You have spark and squirt (and we'll assume suck, as in air). You said that you checked squish as well. As others have said, timing could be the issue, as could the amount of the others.

Or your timing belt snapped... <img src="/forums/images/graemlins/nana.gif" alt="" />

HUMMER .25: No need to compensate.

1989 Dodge Raider: 3.0/5
1992 Chrysler LeBaron Convertible: 3.0/A
1994 GMC Safari: 4.3/A