Andy,
I agree with the others saying it could be an exhaust leak. Another option to
look for is the vacuum advance, which you say is not working. As far as I know
one of the functions of the vaccuum advance is to advance the ignition timing
when decelerating. Gas is burning slower when decelerating (don't ask me why,
read it somewhere) and with vacuum advance not working a certain amount of
unburned fuel will leave the cylinders burning in the exhaust causing
backfiring.
Eric BT7
Heinsberg/Germany
-----Urspr|ngliche Nachricht-----
Von: andy65 [mailto:andy65@snet.net]
Gesendet: Dienstag, 8. Juni 2004 17:49
An: List Healeys
Betreff: pop and snap backfire on deceleration
BJ8 - When I decelerate I often get loud pops and snaps and sometimes a
backfire that sounds like the crack of a rifle shot. Only happens when
decelerating briskly and foot is off the pedal or less than one quarter
throttle. Plugs look normal to blackish. Vacuum advance is not working.
Checked timing and it is ok. Otherwise seems to run fine. Where do I look
next?
Andy
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