Miata Mailing List: August 1994, Message #7
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   From: BILL.ALLEN@metrokc.gov
Subject: FW: An Idle Story
   Date: Mon, 1 Aug 1994 11:44:07 -0400

This was sent to the net last week but I didn't see it on my dailey digests. 
Maybe I didn't get some digests last week?  They seemed to be short a few.
Bill Allen
________________________________________________________
From: Allen, Bill on Tue, Jul 26, 1994 8:52 AM
Subject: An Idle Story
To: miata(a)jhunix.hcf.jhu.edu

Last night Chuck Sider, a member of the Puget Sound Chapter, called me seeking
help on a bad idle problem with his Miata.  It seems he was driving around in
the heat wave we had last week, stopped to do an errand, and the engine stopped
with a loud bang.  On restarting, the Miata would barely run, it just wouldn't
idle.  We talked through the various checks he had done.  It would run fine at
high revs.  The idle roughness and dying was too severe to be an idle
adjustment or droop situation.  He could catch a manifold pressure reading at
idle, 17 inches of vacuum, which seemed adequate.   He had inadvertantly
stroked the idle control valve by disconnecting the harness, so it wasn't a
stuck shuttle.  We concluded he should go in and see a dealer and I shared with
him the info I've heard  and experienced with the various service shops and
their managers and technicians in the Seattle area.  In closing our
conversation, I relayed a story I heard from Lester Seal of the Mass Miata
Chapter about a Sebring Supercharger owner who drove it so hard he blew a plug
off the inlet manifold.  The plug is a rubber, bullet-shaped cap on a
connection located on the back-side of the rear-inlet-runner to the engine from
the inlet manifold log.  It does not have a clamp on it.  It and a
similar-looking cap on a jacket-water opening on the rear of the engine
reportedly serve functions on the 323 from whence our engine came.  Anyway my
thought was perhaps Chuck had experienced some sort of backfire and the
pressure blew the cap off.  We said goodbye and after about 10 minutes, I got
another call saying,>Smokey<, you did it!  Thanks alot, you saved me a half-day
off from work going to the shop!  Chuck had fashioned a temporary plug and the
Miata returned to its smooth and familiar idle.  I'm truly a shade-tree amateur
mechanic, and it feels great to be able to help someone!  Remember that plug! 
I went out and put a clamp on it, immediately, as I have an Eaton supercharger
on my gleaming red delight.
Bill Allen