MAC11 update

[Ben Swann]

Cody,

That is a good clarification - what this also means is that in order for the primary
signal to be generated, both flywheel sensors need to be present and signaling and they
must sync. up with the Hall sensor in the distributor cap.  This also triggers the fuel
pump.  From then on out, the primary goes through the Darlington Transistor/signal
amplifier mounted on the coil then through the coil, cap and rotor and out through the
wires and plugs to ground.  So the only things that could be breaking down are coil,
cap, wires or ground.

Once again, unlike the earlier cars that used only hall signal to generate primary( five
window hall distributor), there is no ignition timing adjustment - distributor must be
in a set position, which is preferably dead middle of the hall window.  The ECU does the
rest of the timing.

One possibility that breaks this above "rule" down is that the timing belt has slack
and/or window is just on edge so that the ignition slips out of window.  Usually this
reveals itself in a no-start condition that is temperature related.  

So - you might have a breakdown in the spark output side, but I think you have covered
thost bases well.

Ben 

-----Original Message-----
From: John Cody Forbes [mailto:cody at 5000tq.com] 
Sent: Wednesday, September 10, 2008 1:08 PM
To: Ben Swann; 'Rick Houck'; 'Louis-Alain Richard'
Cc: quattro at audifans.com; 'P Cole'; 'Ado Sigal'
Subject: Re: RE ; MAC11 update

What Ben means to say is that all is well with primary ignition (signal output to the
coil), but the ECU knows nothing about whats going on in the secondary ignition
(everything between the coil and plugs inclusively) and won't store codes for these
areas. Thats where the scope comes in. Get ahold of that scope, your problem will be
diagnosed for sure.

-Cody


Ben Swann wrote:
> Again - what do the MAC-11 codes say.  If 4 4 4 4 then all is well 
> with ignition.