Quoted from swirvin:The left slingshot on my TFTC will not fire in game play or test.The coil is good and will fire when the collector is grounded...
Are you grounding the Tip122 collector or the pre-drive transistor collector or ? If it works grounding the pre-drive collector, then I would go back to the logic signals. Have you checked the logic levels with a scope or logic probe starting with the PIA while in Diagnostics->Coil Test? Is the PIA socketed?