My spare van that is not driven often would not start. Started on carb cleaner so traced fault to in tank fuel pump that seized.I replaced the pump.Rail fuel pump ok. engine started ok and runs smooth above idle but would not idle smoothly as before .With a little throttle runs smooth,however it bogs when the throttle is pressed quickly. Very uneven and lopey idle and is blowing black smoke and has turned on check engine light. I cleaned the air bypass,checked the press regulator hose for vacuum no smell or gas evident at the regulator (diaphram not split) Checked hose to map sensor. Its had new wires plugs cap rotor recently unrelated to this issue.The engine has 63000miles. Any help or suggestions appreciated. Thanks

 

you may having problem with the accelerator puymp buiold in carburator the diaphramg must be dry out

 

Sounds like a fuel problem. I have an 84 E150 mark III had a big vacum leak, since i pluged the vacum port it has no hesitation on initial acceleration nad never did with the vacum port unpluged. My 2 cwents.

 

You need to pull the codes. It sounds like a bad o2 sensor or bad map sensor. It may even just be in need of a good tune up. Take it out and DRIVE it. I mean really drive the hell out it, it may just be carboned up.