Hey, I have a 1988 k5 blazer with tbi 350/700r4/np208. I have this strange issue where when i start driving, the timing advances then immediately starts retarding, causing the truck to be very sluggish. This is accompanied by a awful idle when warming up and sometimes code 45 (running rich). I have replaced coil with accel super coil, e3 plugs, brand new ac delco knock sensor, carquest plug wires, duralast dristributor (with ac delco original icm and accel cap+rotor) ive swapped the knock sensor but it still retards, could it possibly be an issue with the esc above the passenger valve cover??? is the icm able to retard timing??? any help is greatly appreciated!!!