Strange as it sounds, the Chevette diesel engine (made by Isuzu) is actually worlds better than the gas engine in those cars. Not saying much there though...
The Mazda diesel in the Tempos wasn't so hot. My wife had a gasser Tempo when I met her. I HATED that car. The 1.9L pushrod engine in it was actually pretty good however. Only good part of the car. The electrical system in the car was terrrible. I had a fun time keeping it running. Dash switches (stupid rotary blower switch) were crap. The CV joints and brakes were crap. It almost burned to the ground a few times, and none of the wiring had been tampered with. My "fixes" were worlds better than the factory crap. They were still holding together 10 years later when her stepfather was in a terrible wreck that totalled the car (and killed their poor old black lab).