Diesel Misfire?

[feenix]

Was driving my 200tdi today and was tonking it up a hill (4th ~3800 RPM) overtaking and the engine seemed to misfire.  I heard a pshhhht sorta noise (sounded pneumatic) and the engine missed a beat.  Slowed down immediately and pulled into a car park, got out and noticed a trail of liquid behind the disco.  I'm guessing it's water or diesel because it evaporated fairly quickly.  
I'm at a loss as to what happened and where the leak is/was because I can't find any trace of fluid in the engine bay (other than the usual).
Checked all fluid levels, coolant seems a little down, lost a coupla pints since I topped up a month ago.
Any ideas?

P.S. thanks for the info on that vacuum pipe - fitted it back in place :)

[johnpirate]

Mine used to make a pneumatic sound when the turbo pipe had collapsed in on itsself It got quite gutless at times missing and losing power a previous owner instead of replacing it had trimmed it and taped it up.Replaced it ran great afterwards.

[feenix]

I've had a look at the pipes, they are old, and the one from the intercooler to the inlet manifold is bulging a bit, so could do with replacing.  There doesn't appear to be any splits though.  I'm wondering if the wastgate could make that sort of noise.  Does it vent to atmosphere or straight to the exhaust? Also is there a safety valve of some sort associated with the turbo?
Have been driving it today without any problems  :?