Miata Mailing List: August 1994, Message #264
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   From: BILL.ALLEN@metrokc.gov
Subject: Backfires & Surging
   Date: Mon, 8 Aug 1994 23:43:53 -0400

A string last week asked why would a Miata backfire on the intake side and one
person noted some surging on acceleration in his Miata.  My supercharged Miata
sometimes surges during moderate acceleration, so I was curious and called a
couple of reputable and well trained Mazda service managers.  I really didn't
learn much.  Great information,hunh!?  Both couldn't guess why a backfire in
the intake.  Obviously, some fuel remained in the intake manifold and likewise
something ignited it.  It's not common.  The slight surging was considered
common and one of the mechanics suspected it was related to flow through the
PCV valve.  I have had the engine check light come on at moderate load and
around 65mph.  I can put it out by backing off the throttle.  This mystery may
be solved by putting the unit on an analyser, which I will do as soon as I can
make time. FWIW.

Bill Allen