RE ; MAC11 update

[Ben Swann]

Rick - have you pulled codes? 

As far as similarity with MAC-02 from UrQuattro, they are not.  All Control exlectronics
for both ignition and Fuel are contained in the MAC-11.  There is not much in the way of
fuel control either for the MAC-11.  

As I continue to mention, once the MAC-11 system starts and runs, then you can pretty
much rule out ignition. If timing is set per procedure - ref. prior more elaborate post
that got filtered from main list - shame as good info was in there and I don't want to
retype all that.  Basically - Set and Forget! The only other things and you have ruled
them out AFAIK are wires, plugs, coil, cap and rotor.  Move onto fuel side of things.

I think I also now understand that your EFI systme is not taking a trigger from the
coil, but instead is triggered by pins mounted on the cam sprocket?  A little lost on
the details of your actual configuation.

Again - what do the MAC-11 codes say.  If 4 4 4 4 then all is well with ignition.

Ben

-----Original Message-----
From: Rick Houck [mailto:rhouck at neo.rr.com] 
Sent: Tuesday, September 09, 2008 10:38 PM
To: Louis-Alain Richard; cody at 5000tq.com; 'Ben Swann'
Cc: quattro at audifans.com; 'P Cole'; 'Ado Sigal'
Subject: Re: RE ; MAC11 update

Louis-Alain,

I have read through the suggestions on SJM's site, and feel that I have tested or
eliminated things sufficiently, but since I have not yet found the problem, I am
obviously missing something. Opening the ECU was one of the earliest things I did, since
the problems started at a rainy track event. I found no evidence of moisture or water
tracks, but dried it out in the sun just to be sure. After no improvement, I ordered a
spare ECU and distributor from Force5.

I have at least two of each of the major ignition and mechanical components, and I have
tried about every combination of ECUs,plugs, wires, dist caps and rotors, complete
distributors, coils, flywheel RPM and TDC sensors, knock sensors, fuel filters, and
COMPLETE ENGINES. Nothing so far changes the situation except turning the distributor
counter clockwise.

It seems unlikely that I have two identically bad components, but maybe I do. It also
seems unlikely that both engines have a sheered key on the cam or crank, but the
relationship between the distributor rotor and the TDC trigger is good enough for
starting but not for running at higher revs. The ECU is getting full voltage during the
problems, and I also have confirmed ground (don't remember pin numbers now). As Ben
says, ignition seems to be satisfied enough to start and run properly for the first 25%
of the RPM range.

Cody, I have some very loud exhaust backfires (3" from turbo back with no cat), but
others come back into the intake system. I have been concerned that I may damage my
turbo or intercooler plumbing. This indicates to me that the timing is getting confused
at some RPM, or that the plug is firing at an improper time because of arching. When I
changed plugs last week
(again) the Bosch's had a dry carbon coating, but IMO nothing out of the ordinary for an
engine running at low speeds. New plugs are NGK's, but results are the same.

Rick
about to give up

[snip]
> Guys,
>
>
> I think things are pointing to a wiring problem, but have a couple of 
> questions first: Could a turbo that doesn't spin as easily as when it 
> was new cause backfires?  My Garret GT2871 ball bearing turbo still 
> spins up (as I can see when the cone filter is off), and I can hear it 
> coast down after shutdown, but it is not quite as smooth as when it 
> was new 3 years ago. I have not checked end play, but it certainly is 
> not enough to cause any contact with the housing. I can't get enough 
> RPM to get the boost up much, but it does get started up the dial 
> before the backfires start.
>
> I don't have an o-scope, but I think it is time to find someone who does.
>
> Rick