Projection

[Squash]

Indeed the 4Di will function quite nicely without the O2 sensor.  I
tried it on mine!  And, i have the manual for the marine projection
handy right here for reading at work!  Without the O2 sensor, cruising
efficiency is lost, but if your fuel map is dialed in correctly, you
shouldn't need the O2 sensor.  I have actually unplugged mine to see
what it would do.  I drove it to work for a week.  That is how i tuned
my fuel map.  The holley guys are OK.  There are only 2 or so that know
much about the digital systems.  let me know if you have any questions!
-- 
Andy Quaas

Mike Jones wrote:
> 
> Andy,
> 
> Can the 4Di be used without the O2 sensor?  (I realize tuning becomes more
> critical.)  Due to water-cooled exhaust system my marine application makes
> implementation of an O2 sensor difficult.  (One possibility I thought of is
> to tap into the currently blanked-off EGR port and run a seperate mini
> exhaust, but this raises questions of its own, such as how much flow would
> be required to give accurate feedback, where to discharge this exhaust,
> etc.  So for now no O2 sensor is my goal.)
> 
> Holley is advertising a marine 4Di which should go on sale in a couple of
> months.  I've spoke with Holley tech twice.  One rep said that the marine
> 4Di must use the O2 sensor and the other one said that it wasn't necessary.
>  Sadly typical for Holley.
> 
> Thanks,
> 
> Mike Jones