Re: Wait one friggin' minute!

[Mick <bmwmick@xxxxxxxxxxx>]

At 08:46 AM 6/21/2006 -0400, you wrote:
>-----Original Message-----
>From: ABSDoug <absdoug@xxxxxxxxx>
>To: oilheads@xxxxxxxxx
>Sent: Tue, 20 Jun 2006 20:47:04 -0700 (PDT)
>Subject: Wait one friggin' minute!
>
>
>    I was told by someone who should know... I know that an Oilhead throws a
>spark on both cylinders (wasted spark) but does the FUEL INJECTOR GO OFF 
>TOO!!??
>
>
>Doug,
>I read that in one of the repair manuals once,  I remember cause I thought 
>it quite odd but when you
>consider that at 4,000 rpm that injector fires 66 times a second  Of which 
>only 33 of them are on the compression
>stroke   it takes all the firing it can get to charge the cylinder.  I 
>suspect that it really is spraying fuel
>in a constant ( to us anyway)  and is really just varying the rate of flow 
>slightly for the trottle control.
>
>Our machines are amazing when you consider what they can do in a second of 
>time..and yet we
>get all upset if it just misfires even once and we notice it...
>
>paige

Paige,
   The upper Hall Sensor (TDC) controls the spark and the combination
of TDC and 180 (BDC) sensors develop a signal called TD.  This TD
signal is used to control the injectors.  I've seen R1100's with good
spark and NO injector pulses.  In this case, most likely the lower (180 or BDC)
Hall Sensor has failed.  The reverse is also true in that the injectors can
be operating just fine but there is no spark event in either cylinder if the
upper Hall Sensor (TDC) is defective.

Mick
Tucson

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