I would hit the wrecking yards and pick up a couple of coil packs, they used these same packs on the V8 Fords, just FYI
They run about $75-$90 new, $50 on ebay, wrecking yard is "what ever price you can get", lol, but bring OHM Meter to test, not fool proof but best to test first.
Well something is amiss if adding a ground caused problem to surface, it does mean something is wrong but can't say it is ICM or coil.
I would ground to engine, frame could be a floating ground which may be an issue, PCM(computer) is usually grounded on firewall and there is a ground strap from engine to firewall, or should be.
Frame is isolated from body and engine by rubber mounts, or should be, lol, and it should also have a ground strap from battery's ground on engine to the frame.
These ground straps are often removed during mechanical service and then never hooked back up, "hey it's all metal, so it's all a ground", but this isn't true.
4 grounds on vehicle should be:
Battery to Engine(for starter motor)
Engine to firewall(for computer and dash board)
Engine to frame(for lights and fuel)
And there should be a smaller lead on neg terminal hooked to Rad support frame(for head lights)
Last edited by RonD; 10-19-2014 at 03:14 PM.