87 Toy Supra N/A, Running on 4 Cylinders

[wilvelas]

Ok, here's the situation:
- Let a friend borrow my 87 Toyota Supra N/A for a few days and when I got it back it was putting. Having reason to belive I was dealing with a misfire I pulled each plug wire with the engine running. Cylinders 3 and 5 had no affect when the wires were unplugged. Assuming bad wires (wires were dated 94) i went ahead and replaced them with Prestolite Pro-Fit wires. At the same time I inspected my spark plugs and found some dirt and grease on plugs 1 & 2 but the electrode and ground were fine. I reinstalled all the plugs, ran the new wires, put everything back together and the car was still misfiring. Assuming my friend was a cheap ass, I refilled the tank with supreme and pulled the injectors to check them for being plugged or gummed up. Nothing noticable, unfortunately I have no other way of testing them other than visually. I put the plugs back in, in a different order, and took the car out. About 20 miles down the road the car starts kicking and bucking like a bull and all power is lost (feels like a four cylinder!) I haven't had time to check what cylinders are misfining now but I wanted some ideas on what could possibly be wrong. Thanks in advance everybody.

- Wil

P.S. I did a compression check and got about 180psi on all six cylinders (variance of about 5psi between cylinders). The engine was just put in about 200 miles ago (used but compression test was good as was leakdown test).