hi my 87 944s has developped a missfire, lack of power trying to excellerate around 60mph plus .engine runs fine and eccellerates fine through rears.starts first time every time.when travelling a distance on motorway 20 mile or so problem dissapears and she runs fine untill ignition is switched off, when started again same problem.thought about dme but doesntthis causecutting out

 

I would suspect the ignition control module which is present on the 'S' cars. It is mounted to the wheel well, right behind the headlights (in the engine bay itself). On US cars, it is on the left/drivers side.

 

would this be temperature related i was thinking engine temp sender up the spout