Low boost/lack of power MC2-engine (MC dual knock)

[George Selby]

At 03:00 PM 3/16/2009, you wrote:
>I agree that the problem sounds related to a turboleak.
>But lets say it is a turboleak. How can a turboleak only occur
>after 30-60 minutes of driving? And if I turn the engine off and let
>it sit for a while, boost is again up to what it should be, 1.4 bar.
>I mean.. a periodic turboleak? Even plausible?

Yes it's possible.  Some bits are attached to the car, and some to 
the engine (The fuel distributor and intercooler are attached to the 
car, while the turbo and throttle body are attached to the 
engine.)  The engine moves around while you are driving, which can 
open and close off tears in the tubing between the aforementioned 
items) and cause seemingly random leaks in the tubing.  Generally, 
problems start out occurring on a slight basis, then start happening 
more and more often, until finally the car won't start because they 
are so bad.  I had this happen on both my 89 80 and my 90 200.

One other thing I'll mention as a possibility, I was having a problem 
with random power loss on my 200 Turbo, and on a lark changed the 
fuel pump relay.  Problem solved, until the intake rubber elbow 
coming off the turbo tore, and presented similar symptoms.  Fixed 
that a about a month ago, and now I'm back to full power all the time.

George Selby