The engine lacks power, has no acceleration, engine stalling intermittently. Fault intermittent.

Road-tested the vehicle and could reproduce the fault after coming to a stop and then going to take off. The engine has no power, slow to accelerate. If you put the transmission into neutral and hold the throttle to the floor, the engine would slowly increase revs, then come good, and free rev ok. Drive the vehicle again, ok, until you come to a stop again. The engine would idle roughly, then stall out.