The engine is always running out at the Escort.

Hello. My acquaintance drives an Escord Tunier Bj. 10.94 with 1.4 liters and 55kw respectively 75ps. MKB is not known to me. Now she has the problem, which as soon as he temperature pointer at norm is the car went out. so first I changed the ignition cable + ignition plugs (original Ford was used) because the scrap were. now it went about 3 months. and now the whole game again from forne. Have put in and let it warm up and have noticed that when it gets slowly warm and one of the gas only if, as I said, he is in the norm range of the display, the speed is so low that he goes out. Hope someone can help me quickly. P.S. Error memory is leeeeeeeeeeeeeeeeeeeeeeer. Mfg Chris