Surging Problem

Hi,

I have a 1990 Plymouth Voyager. When I am on the road, my van seems to be surging. Meaning, as I go along, it seems to be bucking. I put a new rebuilt engine and fairly new fuel pumb and STILL, having the same problem.

Please help,

lgreen

have u checked the pcm for any trouble codes? is the check eng light on. the most common sensor malfunction that causes surges is the map sensor. check the underhood decal vacuum diagram for its location and if there is a vac hose, check for cracks or maybe unplugged. check the eng computer (pcm) for any codes i believe a code 13 14 or 15 is related to the map sensor