try pulling a plug from the motor, recconect the wire, and put the end of the plug on a ground, crank it and see if you get a fat blue spark, if you do, then spark is good, if you get a yellow spark, spark is weak but should still make the motor sputter, if you get no spark at all, then you'll have to start diagnosing your distributor, find out if the pickup is functioning and so forth... a common problem caused by this when people pull their dist, is they damage the cap and dont realize it.... a small hairline crack is enough to cause spark scatter, which will make it spark very weak