Not seeing the condition of the vacuum lines, hearing/seeing the sputter and backfire, or having a scan tool connected, my first suspicion would be spark plug wires and spark plugs. But also make sure there are no vacuum lines disconnected/cracked and that the intake air tubing is securely connected between the air filter and the throttle body.

-Rod

 

Rod, I replaced 5 out of 6 plugs. the rear passenger side I couldn't get to guess I'll have to pull the tire to get access. as for the air intake tube my buddy managed to lose the clamp on the MAF sensor side, so it's bypassing the MAF sensor so I suspect that to be the issue

 

Yeah, that back plug on the passenger side isn't too bad from the wheel well area. It will be easier if you pull the wheel, but is doable with the wheel installed as long as you can get the weight off the suspension to give you enough room to see what you're doing and get your arms above the tire.

The missing clamp at the MAF could definitely be causing the symptoms you describe as well. You may want to give all the plug wires another tug as well to make sure the wires are snapped on well.

-Rod

 

Check that the starter relay up on the driver side fender wall is goo, and MAKING good contact to vehicle (that's it's ground). Had a early 80's Capri, that I had to wiggle it around under the hood until I got a good ground. (Eventually bought a couple of larger self tapping screws, and never a problem after.