EFI + MAC-14 maxing ataround 5k RPM

Ben Swann benswann at verizon.net
Tue Oct 23 19:44:50 PDT 2007

No - distributor sends a digital signal and is set to middle of it's window.  I have
rulled out any physical distributor issue.  Could be a problem with voltage breakdown at
high RPM, but now I'm leaning toward fuel injectors and the Megasquirt pulsewidth
settings that drive them.  I'd consider the wiring to the coil to be fairly overkill -
more massive than was originally used with the MAC-14 setup - keeps looking more like
injector and pulsewidth setting or ??


-----Original Message-----
From: Kurt Deschler [mailto:desch at alum.wpi.edu] 
Sent: Tuesday, October 23, 2007 10:40 PM
To: Ben Swann
Cc: quattro at audifans.com
Subject: Re: EFI + MAC-14 maxing ataround 5k RPM


Is it possible that your distributor is timed wrong and the rotor is not 
aligned with the cap when the spark advances? The ignition timing could 
still be correct even though the cap is positioned wrong. Just a thought.


> Message: 4
> Date: Tue, 23 Oct 2007 18:32:57 -0400
> From: "Ben Swann" <benswann at verizon.net>
> Subject: RE: EFI + MAC-14 maxing ataround  5k RPM
> To: <audi at humanspeakers.com>
> Cc: urq at audifans.com, quattro at audifans.com
> Message-ID: <017d01c815c4$ac3f1dd0$0501a8c0 at swansong>
> Content-Type: text/plain; charset=Windows-1252
> Huw,
> I'm absolutely certain there is no fuel pump relay - I wired this thing completely and
> purposely left out that feature for now.  There is a relay, but it is a basic
> relay that is keyed on with ignition and takes power directly off the battery.  I am
> going to put a heavier duty relay on just to be sure there is no reliability problem.
> The power wire segment to the pump is under 3' and using #10 wire.
> I mentioned not beig a fuel pump cutout problem in my original post knowing that this
> would be the first thing folks would think of.  So rule it out completely.
> There is no RPM or boost related cutout due to relay or intended/programmed function
> the MAC-14 or Megasquirt.
> Ben

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