modified inlet manifold chamber

Well I decided to open up my inlet manifold chamber as it was rattling, obviously the valves inside which locate onto ball and cup sockets had come adrift (broken on 3 valves).
Now with the cost of replacing said item I figure the valves were stuck open anyway just rattling around.
I decided to remove the 3 valves and put her back togethor.
Well it now runs like crap, backfiring in the inlet, and then not running at all.
Question is this:
Would removing these valves cause the problem as previously the they didnt work anyway?
The vacuum seems to be knackered on the brakes too.
please humour me guys.

No Humour needed, you simpley need to go and buy a new manifold, they are not ment to be taken apart and repaired.

Check this thread
www.landyzone.co.uk/lz/f9/freelander-v6-manifold-rattle-62618.html