when my mate first got the car it ran ok until it got to 3.5 k then it starts kangeroo hopping then the problem started to occur when ever you accelared slightly fast and now the car wont even move it revs up fine when its stationary but wont rev under load eg pulling away the problem ocationally subsides when the engine is cold we have change the coil pack ecu and all the connector but it still isnt working any ideas