[MPDano]

Ah sorry, not up on the EFI stuff. Mine is CIS so I don't have a MAF. I also didn't know this was a running car beforehand. Hmmm, all this from just getting Fuel Rails and Spider Powdercoated doesn't seem right. Unless you either bumped something else in the R&R. Backfire sounds like timing. Mine did that when timing was off. Are you sure when you removed that distributor bolt, it didn't ride up and move a gear tooth or 2. I would verify all your timing marks are lining up as well as your Distributor Rotor.