Vacuum leak?

[cняis]

I noticed there was a recent thread regards 16v idle trouble/vacuum leak but i wondered if it was different for the 8v...

The old red mk2 (8v digi PB) isnt being used much at the moment and has developed what i think is an air/vacuum leak. I think its jealous of the other half's mk3 (which i spent about 4 hours cleaning today, and now gets used as the daily) 

it almost stalls when i dip the clutch, then the revs bounce around a couple of times before settling at the normal idle speed. also the exhaust is popping a bit on over-run (sounds nice but isnt how it should be!)

i have checked the usual suspects but cant see anything wrong with them:
- rocker cover breather/'flying saucer' grommet
- all the vac pipes i can find including the one for the MAF mpg read out. some of the rubber ones are looking cracked but not split.

what else should i be checking?
- idle screw o-ring?
- idle control valve?
- anything else?

thanks chaps

[DarnPB]

Check the vacuum pipe that go to the bottom of your air filter box and make sure that they are in place. One of these operates a valve within the airbox. You could disconnect that one, blank it off so that it is airtight, and take the car for a run. If this cures the problem, then the valve is leaking. Also, how are your brakes? Check the piping going to the brake servo for any splits and that the non return valve is working properly. If there are any problems within the servo system, this could cause you no end of problems and is very difficult to find. Again, to fault find the brake servo, disconnect the vacuum pipe from the inlet manifold to the servo and blank it off so that it is airtight. Then take the car for a spin. But be aware, YOU WILL NEED TO APPLY MORE PRESSURE ON THE BRAKE PEDAL AS YOU WILL HAVE NO SERVO ASSISTANCE! If the engine runs more happily, then the problem could be the servo or associated plumbing.

[cняis]

nice one for the in depth reply darnPB... but i overlooked the flying saucer grommet...   :embarassed: it looked ok but when i tried to remove it, it just fell apart. it was only 2 years old!