Hello everyone. I have a 1995 k2500 with the 5.7 TBI. I recently did the intake manifold gasket. It was running decent bur not the best so I checked the ignition timing and it was a little off. I followed the Haynes manual and it was idling smooth until I plugged back in the EST. Once I do that it ran rough and would eventually die. Any ideas why it would be doing this?