Have a buddies truck that died on the way home this morning, ran fine but when it warmed up it started running real rough and finally died. Once it cooled down it ran well enough to get home but once it was home idling it warmed up and died again. No spark, I'm 99% sure it's the TFI module on the distributor but would like second opinions. I was thinking it could also be the coil but I know the TFI is a more common problem. The engine is a speed density setup, so I was curious if it could be something else I'm over looking. Opinions?