YES I UNDERSTAND THE MONEY SITUATION WE ARE ALL THERE TOGETHER. But it sounds like the wires was an improvement. Are you positive the fireing order is right recheck it. I have got a wire crossed many times very easy to do.
Check all vacum hoses to be sure they are connected and no holes in them.
Check intake manafold for vac leak. Fuel pressure very important on this eng. When you press the accell and eng backfires it is not getting enough fuel. Did you replace the fuel filter?
vac leaks at hoses
vac leaks at intake manafold
determine which cylinder is misfireing
this could be a fuel injection controller
remove intake look for broken plastic lines for poppet valves
look for raw fuel inside the plantum chamber
the vortec has a fuel injection controller it fuels the cylinders through poppet valves these valves opening and closeing right depends on fuel pressure being exact to specs. This is a tough one to diagnose and a new controller is a couple hundred dollars.
This is why you need to pin this prob down to only the cylinder misfireing.
Tuesday, February 15th, 2011 AT 4:37 PM