Just been pissing about attempting to get the diesel fiesta to run again, the tensioner had loosened off, not eblitorated like first thought

timed it up, it starts, revs upto about 2000rpm and then shuts down - and i don't even need to touch the throttle pedal


anyone any gen on why this is happening? as if i have to buy a new car, i can't goto the ring, as i simply cannot affaord both, and i am not using the cossie as a daily drive - 2 miles each way to work will exentually cause a lot of wear