Wire out the MSD and see if it runs. I had so much trouble with my setup like that I used to keep jumper wires handy so I could switch from tbolt only to tbolt w/ msd. Ultimately I removed the msds all together and never looked back. Other than that, make sure your tbolt module and distributor ground wires are good and have solid connections. Check for 12 volts at the + side of the coil with the ignition on.