I have got a 1998 Ford Escort 1.8TD estate which drives fine until intermitantly, it loses power and the engine finally stalls. It starts again fine straight away and runs fine for a while and then plays up again. It usually loses power on going up hills but not necesarially on all hills. Also the heater plug dashboard warning light flashes intermitantly whilst I am driving. I have read other posts on here about this being the engine management system warning that there is a problem and then putting the engine into safe mode but as far as I am aware my car does not have an engine management computer on board. Any suggestions as to what I can check before taking it to the garage please. Thanks