1989 rs w/ lo3

I hate to write a book but its been a rough few months and Im going to try to mention everything in case it adds up to anyone.
First to radiator blew.14 years of crud decided to break looseLuckily I was pulling into my driveway when it went.I replaced the rad and while I was at it replaced the thermostat w/ a 180 degree one.
About the same time I noticed the tach would jump a little as I cruise.Occasionally you could feel the surge too.Thinking it was bad gas I added a fuel treatment.It worked for a few days then started surging again.A tune up was done.The plugs were changed to rapidfires and the distributor and rotor changed to MSD. Again it ran better a day or two then started surging again.
One day at a light it felt reeeeally rough.As I started moving I heard a "pow" from under the hood that sounded like a BB gun.When I got home I checked it out and found a vacuum cap had come off(shot off?).I replaced it but the car still ran rough.Its gradually become worse to the point I can feel it get rough and "drag"(kinda like when you drive through deep water"and then it will let off a massive backfire from under the hood.It will do this 3-4 time between home and work(about15 miles).
Ive checked the aldl and had a code 32(egr).I replaced the EGR and noticed the same vacuum cap from before was off again.This time I dabbed silicone on the hose first(come off now!!! )Anyway even with the new EGR when I test drove it I still ran rough and backfired. And yes,i disconnected the battery to reset the comp.

Any ideas?I hope to have it running for the F-body gathering in Bowling Green next weekend.

 

hmm, did you check your timing at all?

 

For future reference..

1)I had a bad MAP sensor causing me to run rich.For some reason it didnt show a code.
2)the timing WAS off.Seems the 14 year old timing chains about gone.Its stretched so bad its tapping the timing cover!

 

checked your cats for being plugged?