RE: MAP "Adjuster" Works! :'B

From: Shawn Bowen (Shawn@bowen.com)
Date: Tue Jul 10 2001 - 14:36:16 EDT


Hey bud,
        You couldn't post a parts list and basic diagram could you??? That's
sounds very useful for a Supercharged application as well!

Thanks,
        Shawn

-----Original Message-----
From: owner-dakota-truck@BUFFNET.NET
[mailto:owner-dakota-truck@BUFFNET.NET]On Behalf Of Wisotzkey, Rich
Sent: Tuesday, July 10, 2001 8:38 AM
To: 'dakota-truck@buffnet.net'
Subject: RE: DML: MAP "Adjuster" Works! :'B

Hi Bob,
The MAP feeds vacuum information back to the PCM in the form of a voltage
level. It used this level to determine the engine load, and adjust the
amount of fuel being delivered accordingly. With my cam only drawing 11" of
vacuum, the PCM was receiving a voltage of approximately 2.8v. I built a
voltage divider to insert between the MAP sensor and the PCM. I then
adjusted the divider circuit to deliver an approximate voltage of 1.9v to
the PCM, so it thinks it is drawing 16" of vacuum instead of 11".

Now it doesn't flood out when you take your foot off the throttle. The
beauth of this is that the divider does not provide a constant fixed
voltage. It varies just like it normally would with the changing conditions
of the engine. All it does is offset the voltage level back to the PCM.
Best of all, it can be made to work on any engine.

Here's something else real cool about the "adjuster". Since it's
adjustable, you could use it to curve your fuel delivery to pass an
emissions test if you ever fail one. What you wind up doing is leaning out
your mixture to correct an overly rich condition. Real sweet, hun?
Rich

-----Original Message-----
From: Bob Tom [mailto:tigers@bserv.com]
Sent: Tuesday, July 10, 2001 10:43 AM
To: dakota-truck@buffnet.net
Subject: Re: DML: MAP "Adjuster" Works! :'B

At 09:35 AM 7/10/01 -0400, you wrote:
>Just wanted to report the initial results on my MAP "Adjuster". As you may
>recall I had a vacuum problem after installing a high lift cam in the 'ol
>318. After some early setbacks, I can happily report the Dak is street
>worthy now and definetly has an "attitude" to go with it. -- SNIP --

Hey, Rich

I'm glad to hear that you solved your vacuum problem!
Now, you can reap the benefits of that MPI-matching,
wild cam.

What does this MAP "adjuster" exactly do? Thanks.

Bob



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