"I have 2x 1998 4.3 2bl carb f
"I have 2x 1998 4.3 2bl carb fuel injected merc vortecs. They both start and run fine.After about 45min of running under a load,when you bring them back to idle they just won't idle.They both keep stalling.I have replaced the caps,rotors,plugs,carb filters and...