MAC11 update

[Rick Houck]

You guys just jogged my memory. I have been thinking that my 034EFI fuel 
only system is completely independent of the MAC11 ignition, but I also have 
an RPM adaptor for the Innovate Motorsports LM-1 that has been used to 
monitor the engine performance and read out to the LM-1. It is still wired 
in the system, although I have not monitored it lately.

Inputs include a tach RPM signal (ta-da!) from the MAC11, wide band O2, 
coolant temp, and charge air temp. Coolant temp and charge air temp come 
from the sensors feeding the 034EFI ECU, and the O2 is dedicated to the LM1, 
but the tach signal comes from the MAC11.

I think I have something else to check tonight!

As far as the coil goes, I changed to a later sytle 7A coil just AFTER the 
problem came up, and nothing changed. With that said, I did have that one's 
power stage go bad and the engine quit running at all a few days ago. I 
installed ANOTHER one of the 7A type and it is still missing as usual at 
about 2500 RPM. I suppose the failure could be related, but I don't think 
so.

I am going to remove the RPM adaptor that has all the inputs from the fuel 
and ignition ECU's. I will let you know what happens, but I think this could 
be it....wo-hooo.

Rick


----- Original Message ----- 
From: <cody at 5000tq.com>
To: "Louis-Alain Richard" <laraa at sympatico.ca>
Cc: "'Rick Houck'" <rhouck at neo.rr.com>; <quattro at audifans.com>
Sent: Wednesday, September 03, 2008 8:02 AM
Subject: Re: RE : MAC11 update


I'm with Louis-Alain, I think the coil is the next place to look.
Think of it this way - if the flywheel was damaged it's not like the
damage would dissapear at low RPM so why would it run correctly then?
If the pin was off the timing would NEVER be right, unless the pin is
switching it's position in the flywheel in real time ;-).

Here's another data point - the tach is run off the ECU. If there is a
problem in the ignition related inputs (flywheel sensors) the tach
would go haywire or stop working all together. If the tach seems like
it's indicating correctly then the issue is an output problem, not an
input problem. It's entirely possible that the igition coil is failing
and just can't produce a big enough bang when the frequency demand
increases. Rick, whats the chances of you (or a buddy) having an
occiloscope?


Oh and I like this "... gotta love the supportive way folks operate on
the "quattro list" these
days ... " by Steve B. Not only does he write that about Huw's post,
but he completely neglected to read Ricks post and asked Rick to test
exactly what he spent time detailing out about what he did last night.
Good stuff.

-Cody Forbes
http://www.5000tq.com




Quoting Louis-Alain Richard <laraa at sympatico.ca>:

> How about the coil, Rick ? Could it be at fault when the RPM rises ?
>
> Louis-Alain
>
>
>
>