RE: Backfiring

From: Jarrid Gross (JGross(at)econolite.com)
Date: Fri Jun 11 1999 - 15:06:21 CDT


Backfire is an unintended combustion of the air fuel mixture, outside
the combustion chamber. It can occur in the intake, exhaust or both.
Short of your original #2,#3 cam problem, it is most typically ignition
that causes backfire (lean misfire exception).

The easiest way to get a backfire, is to phase the distributor so that
a given cylinder fires while its intake, exhuast or both valves are not
fully closed.
This can occur by mistaking #1 TDC with #4 TDC, which both occur at
the TDC pointer, just 360 degrees out of phase.

Here are some things to look for.

1) Is the rotor pointing toward the #1 cap wire at #1TDC (#4 valves not
closed)?
2) Is the ignition unit/points lined to fire at TDC more or less?
3) Did you pay close attention to fitting the oil pump at #1 TDC per proc?
4) Is the spark hot and occurs every half angine turn?
5) Is the phasing and direction of the wire placement correct? (order is
1342)

Jarrid Gross

-----Original Message-----
From: owner-alpines(at)autox.team.net
[mailto:owner-alpines(at)autox.team.net]On Behalf Of Kurt Eckert
Sent: Friday, June 11, 1999 12:37 PM
To: Alpine folks
Subject: Backfiring

Hi All,

I made a quick attempt to start the Alpine with the correct cam and all I
was able to achieve was a backfire after cranking for a while. Does this
mean anything? Also could somebody please explain to me what the heck a
"backfire" is?

Thanks,
Kurt Eckert

----------------------------------------------------------------------------

----
Kurt Eckert
Sales Consultant
Terascape Software
Office:   (888) 276-7972 x118
Mobile: (781) 929-0020
keckert(at)terascape.com



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