PLEASE HELP, CAR LOST POWER!!!!!!!!

[M11BYH]

Hey can some1 please help me. i have an 54plate mk5 gti. it has been remappd by revo and up until 3 weeks ago it was fine but has al of a sudden lost its power. i have had it scanned by Vagcom because my EngineManagemnt light appeared but then i cleared the faults by mistake. i know it is not the Dv because it didnt appear with any dv fault codes. my friend tells me he thinks it may be the "boost control valve" but i havent got a clue. the boost starts to spool up but at 2500 revs its just an anti climax and nothing happens. i took it to the vw dealership and had them chekc it. they said that no engine faults came up. so i took one of their mechanics on a roadtest to show him the power loss first hand.he drove the car and thought the car was fine but he admitted hes never driven a remappd gti. it just feels standard again, if not slower. i have the fault codes that appeard if anyone wants to know them. the main one was "inlet manifold runner control not complete". i was told there was a procedure i had to follow using vagcom for this and i did this, but still no difference, this just cleared the faults. can some1 please help me i dont know wat to do now.
thanks
Muby

[keyser]

Check the DV!  I know you said there is no fault code but take it off and check it.  With the age of your car you will have one of the early B version DV's.  With respect to the VW mechanic, a lot of them don't know s**t when it comes to remaps. A VW mechanic where I came from said my car h not lost any power, despite me running half power. 

[Kiddfrost]

I agree with keyser, check your DV.

I don't believe VC will throw up an error codes if the DV has split. AFAIK the only way to tell with VC is to compare requested boost with actual boost. A mapped car with a split DV tends to peak at about 1.5 bar as opposed to 2.4bar in VC. I would 1st log the boost just to see what your readings are.
I'm not sure on the other error but see if they are listed on the Ross tech wiki.

[Merlin]

dv

[Peskarik]

tighten intercooler hoses as well

[Saint Steve]

Agree with the above, check the Dump Valve especially because youve had yours remapped, and not looked at before, 4 years old most likely to have a worn out Diaphram.

[TomB]

My turbo wastegate has just been diagnosed as the cause of my loss of power, but it did throw up a boost deviation code.

[No Golf Clubs at all]

Is that the same as the dump valve?

[chungster]

Is that the same as the dump valve?

Nope.

The wastegate is in the exhaust housing of the turbo. It closes to make the turbo spool up to the desired pressure. When it gets there, it opens up to let the exhaust gases out so it doesn't overspool the turbo anymore. it'll open enough to keep turbo spinning to achieve the required level of boost.

TomB's...was the wastegate just seized up and needs cleaning or do you need a new turbo? RedRobin had a similar thing, but the housing had a crack at the wastegate, so he needed a whole new turbo/manifold combo! Hope its not too expensive mate.

[TomB]

Lee, I was told it had just seized up.  However his was built around the same time as mine so I'll get them to double check the housing before they fit the replacement.  I was told they're only £18, I thought they'd be more than that!

Does anyone know the retail price of a turbo?  VW Approved warranty has a £1000 claim limit, so a new turbo may cost me something.  Fingers crossed thats not broken as well!