NO spark, any ideas common problems?

I just bought a 91 stealth r/t from someone who was sick of messing with it...he drove it home from the shop (someone installed a new tranny) and parked it in his garage for a few months to do some reletively simple mods. I believe he removed the vacuum lines/selenoids that hang on the firewall and said it was a common mod., he installed a greddy boost controller (electronic) and some grounding wires....anything else he put on was simple like strobe headlights for shows or something like that...ANYWAYS... when he went to start it up there was no spark! He went to troubleshooting for a while and this is what he replaced/checked--He replaced the cam sensor, swapped ecu's with a running car and still nothing, he even put HIS ecu into another car and it ran fine...he replaced i think 2 more things related to ignition but i cant remember exactly what right now...the engine cranks and gets fuel but there is NO SPARK.
Now what i am thinking is that he probably disturbed some kind of ground/wiring that must have been needed for the ecu to send out spark signals. I havent got the car yet to do any of my own troubleshooting but what i am wondering if there are any common problems associated with these cars that will lead to no spark? Anything to do with the vacuum selenoids? Mayb just a loose wire? Anything is more than nothing and i appreciate any help! Thanks again for any input!
-Matt

take it to a shop

Yea i'm in agreement with gateway, might be the Distributor cap though, just have them check everything ignition related.

He's taken it to a shop, and they charged him 1800 just to troubleshoot.....I'm definitely NOT taking it anywhere...if there arent any common problems then I guess i am on my own...

Well the obvious...but have you check the plugs, wires and distributor?