Sounds like a firing order problem to me. Check that first, then check to see if the coil is putting out good hot spark. Just connect a single plug to the coil, let the plug sit on a good grounded metal piece, crank it over, and watch for blue-white sparks. Any other color is bad. How are your plug wires, btw? Spray some water on them at night; if they glow or look like lightning bolts going between them, they need to be replaced. If it's not an ignition problem, you'll have to start checking fuel system problems, i.e. fuel system pressure, injectors, etc. Check vacuum lines and all the other dumb stuff first. You NEED to get the timing to 10-14 degrees, though. Is the timing light you're using working properly? If it has an advance knob, turn it off, and be sure you removed the spOUT jumper from the TFI harness. Just throwin' shtuff out there, dude. Hope this helps.
p.s. Sounds REEELY dumb, but does the car have gas in it? It can run like junk on a near-empty tank, too, ya know.
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Capri306, Moderator, The Mustang Works Online
1979 Mercury Capri, 5.0L -- C4 -- 2.73
1987 Mustang LX Notch 
[This message has been edited by Capri306 (edited 03-01-2001).]