Re: Engine misfire with A/C on

["Fred Munro" <munrof@isys.ca>]

-----Original Message-----
From: Randy Bindrup <bindy2@azstarnet.com>
To: Quattro List <quattro@coimbra.ans.net>
Date: Sunday, May 17, 1998 9:19 PM
Subject: Engine misfire with A/C on


>Have been noticing for a while that when the A/C is on in my '87 5KCSQ,
>I get a engine misfire in the mid to upper boost range.  I noticed it
>slightly last fall but didn't think it was related to the A/C system.
>It is not the usual "did I forget and leave the emergency brake on" kind
>of drag.  I click the A/C off and it runs up to full boost just fine,
>click it back on and it's back to cough-cough part boost.
>
>I Did a R-134A conversion about 2 months ago, but I don't think it's
>related as it was doing it before.  The hotter it gets, the more
>pronounced the miss is ( ONLY 95 degrees in Tucson AZ today - when it's
>ever going to warm-up here).  Was wondering if anyone else has
>experienced this before.
>
>TIA!
>
>Randy
>
Hi Randy;

    This happens to me the first time I use my A/C every year. When the
compressor kicks on, it feels just like an engine misfire. It gets me every
time - what the ..? Was that a misfire? After two or three "misfires", I
finally clue in that the A/C compressor is cycling.
    Could this be your problem? Perhaps your compressor is cycling rapidly
due to the R-134A or a low charge.

HTH

Fred Munro
'91 200q  251k km