Ford Escort engine jerky problem

[vrooom]

my 1993 mk5 ford escort with 1.4 CFI has this odd problem. The car jerks, dropping the rpm like lead baloon, but didnt stall the engine. It's looses the power, until my engine are warm. Until i shut down my engine, then left it like hour or so, then it does it again. Its quite undriveable, i had to keep rev high and dump clutch to get it moving, in middle of roundabout.
engine done 70k, and pull very strong.

any idea what i should look for, engine bay wise. it had new oil and air filter recently.

jay