Ignition timing set-up
JRECPA at aol.com
JRECPA at aol.com
Tue Aug 26 20:22:59 GMT 1997
In a message dated 97-08-26 12:41:49 EDT, you write:
<< Help ... I've done a lot of work rebuilding a Ford 351W for
a Bronco and am experiencing similar problems to what I had
when I first pitched the old variable venturi carb and EGR
for efi and a regular distributor and DuraSpark ignition
off a different vehicle.
=20
Here's the problem -- timing! (at least that's what I *think*
is the problem)
=20
If I set the timing to give good low end response (requires
20 to 25 degrees advanced at 600 rpm, no vacuum), I get
clatter under load at high rpm's.
=20
If I back the timing off to 10 degrees at idle (closer to a stock
engine setting, it runs okay at high rpm's but is disappointing
at the low end.
=20
I've set the timing to a compromise position of 18 degrees
and now I hear something that "could" be something loose
rattling (that's really what it sounds like) at exactly
"neutral" throttle (i.e. no accel/decel) above about 1800
rpm. This bothers me, as I'm afraid it's pre-ignition (or
whatever it's called 8^) so I'm going to set the timing
back some more before I drive it home this afternoon. >>
Some of the older ford distributors have 2 settings for the mechanical
advance. Just take the distributor apart and you may see that the
machanical advance inside can be taken apart and turned 180 degrees,
and have only 11=B0 distributor advance instead of 16=B0 of distributor
advance. That equates to 22=B0 engine advance instead of 32=B0 engine
advance. Try it to see if this applies to your distributor. This will giv=
e
you 10=B0 more engine advance at idle and still set the advance of the
engine to the same total advance.
James
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