Rdriver

I hope some one can help me out on this. The truck is an 88 with a 305 TBI engine. I have replaced the plugs, wires, dist cap, rotor button, fuel filter and catylitic converter today. The truck won't start without holding the gas pedal to the floor. When it does start is is really rich and doesn't hold a consistant idle. I thought it might be the map sensor, but after testing it with a voltage meter it read as it should. I was reading about symptoms of a bad ignition control module and I am thinking that might be the problem. But there are so many sensors, and I am not getting any CEL's to go by. So any ideas where I should go from here...