Sputter, no idle, no power, hard-start

[Slick84GN]

Here I am again! Seemed to figure out the parasitic drain on the battery. Aftermarket theft deterent system, previous owner installed a on/off switch and when the system is off no parasitic drain (that will help the thieves). Anyhown, just recently when for a ride and could not start the stock '84 after a short cruise. Once started the engine had no power, sputtered and would generally not run. Almost impossible to restart. New plugs, wires, MAF sensor. I'm not sure about any codes and need to replace the fuel filter and check pressure before going much further, any other ideas???