valve needed

[Clare Snyder]

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>---------------Original Message---------------
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>Thank you for the suggestion.  The obvious answers often go right past me.
>
>The literature I have available over the phone with my son shows an air
control valve on a '86 Subaru SPFI system.  Is this the device? 
>
No, the part I am referring to is not part of an EFI system, at least as far
as I have been able to determine. The air control valve you speak of is the
idle speed control. There is a possibility you could use this device, but
it's flow capacity is an order of magnitude higher than the unit I was
thinking of.

According to "how to keep your subaru alive", page 206, '80 California
Soobs, all 81-82 models, and all 83-84 non 4wd, non California models have
Electronic Control Carbs. These "duty solenoids" regulate the air/fuel ratio
in response to sensor input.

The units I have, (have one in my hand) bolt onto the intake with 2 6mm
bolts each, stand 2.5 " +/- high, with 2 3/16" hose nipples on each, at
roughly 15 degrees separation. Each has a 2 wire oval plug. I am unable to
find any identifying marks or part numbers, but the coil section is roghly 1
" in diameter, steel, with a square flange with 4 screws connecting it to
the aluminum valve. Looks a little bit like a short, stocky, slightly
mis-shapen injector with no tip.
>>
>>
>How about setting the mixture a tad rich, then add a calibrated air bleed,
>using the duty valve from an electronic feedback Subaru EA81 2bbl setup? It
>is designed to run on a PWM signal controlled by a black box in conjunction
>with an O2 sensor, so should fit the bill perfectly. Was used on "87 Subaru
>Chaser in Canada, not sure what else. A better idea might be to use a Bosch
>KE Jetronic unit from, say, a VW FOX. The control pressure is controlled by
>a balance valve - vary the voltage, and the mixture varies with it.\ Just a
>thought, but I am seriously considering this system for my SOOB conversion -
>hopefully in a CH601 or Sprint in a couple of years.>
>
>
>>I need suggestions for an appropriate, available and affordable valve to
>bypass some fuel from the distributor block in a port injected CIS system.
>The object is to manage the mixture control of an aircraft engine.  The CIS
>system is from Airflow Performace and much like the old Bendix systems.
>This injection system is used because it is not dependent on electrical
>power.  The main pump is mechanical.  The pressure is set at 25 psi, so the
>distributor block pressure will always see <25.
>>
>>With the system I am building, the manual mixture control will always be
>able to override the electronic control, again relieving the system of
>ultimate reliance on electrical power.  We electronically spark one plug per
>cylinder and let a magneto continue to operate the other for the same reason.
>>
>>The challenge is to find a valve that operates much like an injector so
>that a PWM signal can slightly modify the injector pressure.  Other than
>power requirements, the flow rating of the valve is not critical,the flow
>can be controlled with an orifice. The valve needs to pass a maximum of 2
>gallons of fuel per hour, so if the duty cycle is maintained at 30% for
>cruise, a valve rated at 7 gph and capable of following a signal from 4 to 8
>ms wide repeated as often as every 25 ms would be perfect.  Is this in the
>range of injector performance?  Perhaps I could simply inject back into the
>fuel system, using an off the shelf injector but the fittings and hardware
>would likely require a lot of machine work.
>>
>>Perhaps a better alternative is to set the manual mixture control slightly
>lean and then inject a small amount of additional fuel into the induction
>system just past the throttle body with a conventional injector.  Will the
>available devices operate at such low pressure? Is the hookup hardware
>available for a single isolated injector used in this fashion?
>>
>>I agree this is a simplistic approach, but it avoids modifying the existing
>hardware.  Your thoughts?
>>
>>-------------------------------------
>>John Carroll
>>jac at wavecom.net
>> 08/30/97 00:33:59
>>
>>
>>
>>
>>
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>----------End of Original Message----------
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>-------------------------------------
>jac at wavecom.net
> 08/30/97 23:22:21
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