So have a 1989 dodge ram 250 318 fuel injection. I have replaced fuel filter. Coil plugs wires.distributer cap.check vacuum lines everything checkes out. Problem is truck will start fine little hesitant but some pedal motivation and it goes. Idols perfect . No fluctuation. Drives great but when coming to a stop it dies. Or slowing down at all really . And is very hesitant off the line as well as little back fires here an there not often. Very stumped. As besides this truck runs like new. No problems else were no smoke at start or anything . Any help on this problem. Diagrahms etc will be greatly appreciated. It iS my daily need to fix asap

 

How about a vacuum loss when braking? I would check brake vacuum booster.If it dies when slowing down and not applying brakes I would suspect slack in timing chain and gears.