i agree with EVO sti. definetly have some serious blow by issues there. sounds like there is only just enough compression in the cylinders to make the car run if it dies with you hand removed.
the only thing to really cause blow by is rings or piston.
how severe is the crash??? did it damage any of the engine??
id be doing a compression test on the motor to find out where compression is at....sounds to me like you could have a dead GZE on your hands.
ps a mate drove 300km with no oil cap on, didnt affect the running at all. just made a bloody huge mess on engine, from oil.