Engine vacuum leak?

[quk@sievers.com (Phil Payne)]

In message <199610011313.JAA01348@mail4.uts.ohio-state.edu> David Conner writes:

> A recent post by STEADIRIC suggests that if engine runs when dipstick is
> pulled this may indicate a vacuum leak.
> 
> I have two cars with the same engine...5 cylinder NF.
> The 87 5KS will continue running when the oil filler cap is removed.

There's a vacuum leak _AND_ the fuel injection was set up with the breathers 
still attached.  Air bypassing the mass sensor has been automatically 
compensated for during the idle richness adjustment.  Adding more air via the 
dipstick hole doesn't make a great deal of difference - the engine will 
stumble, but the idle stabilisation will keep it running.

> The 89 100 dies immediately when the cap is removed.

No vacuum leaks.  The fuel mixture is set correctly, and adding air via the 
dipstick hole makes, in percentage terms, a much greater difference.

--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club