I am getting a wierd issue I cannot figure out on my 87 4.9L 4 speed. Whenever I give it throttle from 1/4 throttle or less there is a 3 second or so delay, then it begins accelerating and it will buck if i am in the gas hard by the end of the 3 seconds, but if I just give it a little gas it wont buck so hard, it just seems very responsive to throttle position after those 3 seconds. It is annoying as every gear change i let off the throttle and it has a delay. If i keep the throttle above 1/4 the delay does not occur. This happens when engine is hot or cold. It also dies when cold after about 15 seconds of running, but will idle for a long time when warm.

i just got the truck and did some maintenance on it. I replaced fuel pump, MAF sensor, iac valve, plugs, wires, cap, rotor, fuel filter, oil and filter, FPR, fuel pump relay and EEC relay, i think thats it. I was playing with the idea of injectors but wanted to see how it ran after this round first. It ran ok before the maintenance, it would die upon pressing the clutch and slowing down for a turn or stoplight, but it seems to have gotten better after replacing the above. I am just not sure what is going on now. Also this truck has the air pump unhooked it looks like. It also has the engine light on, but i tried getting codes but it wont blink at all. Any insight is much appreciated!