you shouldnt be getting exhaust out the air box. thats a new one. until you get the injection lines purged it'll run like hell. your best bet is loosen the nut on the injector and purge it that way. do this in small intervals you'll need a battery charger as you'll prolly kill the battery a couple times cranking all that time.. if can get pictures/video of the engine bay. something might be amiss there.

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hum.....
1987 300TD 311,000M Stolen. Presumed destroyed