You people who know a lot about programming your ecms and checking data with your laptop and aldl cable. Does it check all your sensors and distributor timing to make sure everything is in check? And if not will it show which sensor is failing and the distributor is working properly? My car when I give it gas it seems to have a hesitation (just reving it slowly while its sitting and cant drive it yet as its not registered). Also it seems like it is skipping a little. I replaced most of the sensors when I rebuilt the engine. I just replaced the IAC, TPS and the MAP sensor this week and no difference on how it runs.

It shows you what is actually happening with the engine ; it is up to you to decide if it is showing to much fuel or not enough spark

If there is a fault in a system the ECM will put up a code you can read with a paperclip.

It is then up to you to use the diagnostics to identify what part of that system is faulty
Could be a wiring / power / ground problem as much as the item in the identified system itself at fault

OH yea I forgot my check engine light is not on and hasn't been on since I had my engine rebuilt.