[Diy_efi] Re: MAP vacuum signal isolation?

[pparaska at comcast.net]

Thanks everyone for pointing out my bad setup - I USED to think
that full vacuum to the advance cannister was the way to go, but
I DID learn that wasn't so good and had previously hooked it
top ported vacuum.  I thank you all for pointing this out to me.
I changed things back to ported vacuum for the advance and 
use the port on the TBI below the throttle plates for the MAP.

On issue is that the port is just above the manifold/tbi mating
surface.  This is probably a bit close to the #2 runner entry
from the plenum on the Holley 300-36 hi-rise dual plane manifold
I'm using.  I did install a large metal case fuel filter in line
from this port to the hose that goes to the Megasquirt, in hopes
of damping out the signal a bit.

As for MegaSquirt ignition control, I hear you loud and clear.
I have the parts for the Ford EDIS-8 setup and a 36 tooth
50 series sprocket that I will dull the tooth tips on to get a
decent trigger wheel out of.  It will sandwich between the 
harmonic damper and pulley.  I will then move to MsnS-E.

Thanks for the help and the memory jog on ported vs full
for vacuum advance!

Pete
http://AlteredZ.com

>From:		"WopOnTour" <wopontour at hotmail.com>  [ Save Address ]
>Subject: Re: [Diy_efi] MAP vacuum signal isolation?
>Date:		Tue, 24 Jan 2006 11:58:53 -0700
>
>Pete
>I agree with the others that have responded- that you shouldn't "T" 
>the map signal line with the vacuum advance. The diaphragm could 
>certainly have a negative damping effect on the vacuum signal.
>But the next obvious question would be WHY would you desire to
> have a vacuum advance at all? Given the refinement of MSnS-E >
>there's really no reason to limit your advance to the confines of the
> mechanical curves of a distributor.So I would suggest you work 
>towards disconnecting the vacuum advance entirely and let the 
>MS have full control of your timing.
>HTH
>WopOnTour