CO adjustment plug question

[camron at worldaccessnet.com (Camron D. Crouse)]

>> Hey all,
>>
>> Anyone know how to remove a partially drilled-out mixture
>> adjustment plug?  I'm working on this '87 16v and the plug
>> has been partially drilled out - the aluminum part.  The
>> hardened steel part of the plug, well, nothing's touching
>> that so far.  From the diagnostics I've done at this point,
>> this thing appears to be running WAY rich.
>>
>> That and I need to see if I can scare up a DPR test harness.
>>
>> Daun Yeagley - Wilmington Ohio

>>Peter wrote:
 > If you want to fill it in, and the stock plug won't fit, or isn't
 > available, I'd clean it up, and use JB Weld on it.
 >
 > Peter
 >
 >
 >

If this hole is left unplugged, would this constitute a vacuum leak and 
contribute to poor running?  Or does plugging it up merely keep the crud 
out?

- Camron from Vancouver, WA USA
    '86.5 Black 16V 2.0L