pls help just replaced the crank sprocket , and cam belt time up checked and re checked all seems good, car started for a few seconds and now will not start just turns over, fill like its a bent valve ,hope not
If you put the timing belt on correctly with the marks and everything in the right place and tensioned correctly, you will not have a bent valve. As you tensioned up the belt, winding it over by hand, you would have felt any interference between piston and valve. If you have indeed bent a valve you mustn't have put the belt on correctly.
Good luck with it because a rebuild is not too much fun - I know because I just did the missus Mercedes engine! 200hrs of work at home!
If it was just one bent valve or at best two, shouldn't the other cylinders still fire up. I'd have a go at checking if there's fuel going through the injectors. And if there is maybe try timing it again.
How long was the engine standing dead while you replaced the crank sprocket?