Car keeps losing power especially when engine is cold

[Fishfury]

Hi guys, I have a cupra 1.8t and seems to have developed a ploblem, when I first start it it seems to be worse, if I hold the revs whilst stationary they will drop and keeps bogging down when I accelerate, I have changed the n75 valve, maf sensor, and spark plugs and also checked for leaks so can eliminate these, any help would b much appreciated
Thanks in advance
Jay

 

[mty12345]

/Hi mate, have you scanned it for fault codes? Is it a genuine bosch maf?

Is it happening just during warm-up from cold? If so then it's more than likely the secondary air system.

 

[Fishfury]

No I haven't had it scanned yet, it was a genuine bosh maf, it seems to come and go to be honest just seems worse when I first start it, it seems to just bog down and you hear the pressure build up, what's the secondary air system? I thought maybe it was the coilpacks? There is a guy local to me who claims to be a vag specialist with some fancy lap top maybe I will take it to him, he wants £85 to plug it in though

 

[mty12345]

He's ripping you off mate, you can buy a 3rd party cable off of ebay and use the free version of vcds yourself http://www.ross-tech.com/vcds-lite/index.html
If you intend to keep the car longterm then investing in the full VCDS is probably a good idea. http://www.ross-tech.com/products.php

It could be loads of things mate, thats why the codes are important. First thing i would check is of air leak in the PCV system, all the hoses under the inlet manifold area. Smoke testing is the only real real to be sure though.

Secondary air runs for first 90secs or so after starting to warm the cat, the cuts in and out a few times in the next couple of mins. Causes mine to misfire at times, but no probs when it's finished running.