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Morning Guys,

Slight problem, I always knew I had a faulty N75 Valve, and was replaced last night, connected everything up correctly, pipes, Airbox etc, now when I start the car it runs really really rough, idling all over the place, and cutting out. This morning I went out disconnected everything, then re-connected bar the air box, and she run absolutely fine, bar the Engine management light and ESP light came on, now once I connected the MAF Sensors onto the Airbox the ESP light went out, however the Engine Management light has stayed on this time, and again she running rough, so I took her out a wee spin and she seems to be boosting incorrectly. Does anyone have any insight into this, or has experienced anything similar...HELP!!!!

Thanks Guys

Iro

Sounds like you've got a major air leak. Probably at the connection of the airbox to the inlet. It's a biatch to get on properly. The fact that the engine runs OK with the MAFs disconnected confirms this. Could be bad MAFs, but unless you've sprayed something on them, then it's a hell of a coincidence.

Shop, nothing sprayed on them mate, Airbox connected correctly, well at least it looks ok, definitely don't have faulty MAFs everything ok on that score. Shop you mentioned Air leak, where should I start looking mate, positive the Airbox is spot on though?

Press down on the back of the air box. It should be firm, not springy.

Air leak could be anywhere in the vac system, but I would start by checking the N75 hoses. By flexing them to change the N75 you might have split them if they are old and perished.

Use the Vagcom to measure your air flow. You should have 3 to 5 g/s at idle.

I would recommend replacing all the vac pipes with silicon hoses. Dave did a post on this somewhere.

Check also your master cylinder hose. Not common but causes all sorts of head aches when it splits.

I've just had something similar on mine and it turned out to be 2 rubber grommets at the back of the air box ?? or so the garage said.

Thanks for the info guys, turns out Shop was right............again lol, Hadn't pressed down on it properly DOH!!!! Convinced myself I had as well....dammit