First of all make sure there are no air leaks between the powerbox/lower inlet and powerbox/throttle body. Then check all of your vacuum pipes for splits.
I would check if the black plastic pipe that runs from the charcoal canister in the drivers side wheel arch to the fuel tank vent valve is still connected at the vent valve end.
All of the vacuum pipes can be connected to the same point at the powerbox and as long as you have left the 's' shaped breather on top of the cam cover venting to atmosphere then it should run fine.

Thanks flame/Glen been really helpful, turned out the guy where I ordered the manifold from forgot to add a nozzle which should of come with the kit!! I have now assembled the thing and car now starts but it is running really lumpy which now questions whether I have connected all the pipes correctly. Has anyone got any detailed photos of how and where they all connect as there seems to be different answers everywhere I look!!! Thanks

Heres a link on how to fit it and the parts needed
http://www.corsasport.co.uk/board/viewthread.php?tid=362354

Here's a video I made when I fitted my inlet manifold. It's not all the fitting as the battery ran out on my Gopro, but it may help u
http://youtu.be/3XloIpOxL38

Not really although there is an old copy of total Vauxhall that had a great how to fit a Mantzel one which is basically the same job. Not sure how you could find that tho. It's not too difficult a job really, as long as you can get the black plastic air induction pipe from behind the engine- if you cut the 'L' off the middle of it from underneath then makes a lot easier. I think Warren G did a guide in the tutorials section here.

Are there any detailed photos for the fitting of these as well?

I think he has maybe put 2 holes there to allow more vac pipes to be run directly into the manifold rather than having 3 or 4 T pieces. Having them all run into one fitting is fine though. Make sure not to connect the S shaped breather that comes off the top right hand side of the cam cover in with the vac pipes or it will mess up the map sensor readings. Just let that one vent to atmosphere.
In short you will be dead on to block one of the small holes on the manifold and run all your vacuum pipes into the other one.

[Edited on 29-07-2014 by flame]

Hi thanks for your reply, yes all three holes have thread in, large hole for the brake servo pipe, second for the map sensor tube and then left with one?? As I say the manifold came without an adaptor for the last hole, so what hose should fit into that bottom hole?

Are there screw threads in the hole at the bottom? If so then you can go to your nearest hydraulic hose manufacturer like Pirtek for example and get a fitting to screw in there. I got ones before that were a bolt with Allen key head and had a channel under the head with a rubber o ring to make an airtight seal- same sort of idea as a corsa c sump plug.
Otherwise if you are going to have an issue matching the thread then get a short bolt maybe m6 would fit if I can imagine the size of the hole and fit that in there with some fibre / dowdy washers to seal it and make sure to use a locknut so it doesn't vibrate loose and end up in the engine.

Please, please can someone help!!

I'm trying to fit a vx performance manifold to my tigra 1998 1.4 16v. I seem to be missing a part which screws into the manifold. There are three holes over on the far right side one large and two small I know what fits into the top large hole and I know the map sensor tubbing fits into one of the small holes as I have part for that but I'm left with the bottom hole and no attachment to screw in?? Also I can't source any tubing to fit the T junction as well?

Can some tell me how to upload images on here as well so I can show you what I mean!

Thanks

Ls