Re: Alternative to Idle Speed Motor...

["David Teitelbaum" <jtrealty@xxxx>]

>From your description of what you did it sounds like the aux air valve 
is now either on or off. There is no in between. The origional "stock" 
idle motor and ECU is capable of modulating ie: it can give you speeds 
in between full open and full closed so it can hold the idle speed to 
a specified value like when you run the A/C or in an automatic you 
stop at a lite and are sitting in Drive with your foot on the brake it 
keeps the idle speed up but not too high. Your system cannot 
compensate for load changes, only temperature changes. IMHO the stock 
system is the better way to go, it just needs to work properly and be 
set-up correctly (something many mechanics can't seem to do).
David Teitelbaum
vin 10757


--- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@xxxx> 
wrote:
> My PRV idles with bypass & balancing screws (like a Volvo). Works
> excellent, but lacks ability to fast idle -- especially useful on 28
> degree mornings. Have engineered an "auxiliary air valve" from BMW 
530
> to accomplish this (am not partial to that particular model; was
> simply soonest ending eBay auction when I got bright idea). Uploaded
> JPG's to #5939's photo album. Text below:
> 
> Aux air valves were apparently used by most other manufacturers of 
the
> time. Are solenoid or coil operated valves similar to heater core 
shut
> off valves. Cold, valve is open, allowing additional engine vacuum 
to
> operate sensor plate (fast idle). Warm, valve closes, limiting 
sensor
> plate movement to bypass screw.
> My valve has 3/4" ports. Stepped down to 3/8" with brass fittings.
> Vacuum source port also turned 90 degrees with an elbow (would have
> preferred model that passes straight through, but hey, this one
> works). Converted two 1/8 NPT nipples to 10x1 to fit manifold and
> upper air assembly (anyone else noted how close those thread 
patterns
> are? Die down right nicely). Used mega hose to avoid collapsing 
under
> vacuum. Line to air sensor plate makes pretty severe bend under
> driver's intake rail, so I reinforced with an internal spring. Also
> had to move spark advance to a smaller adjacent port (see old pic
> titled "R30 - Front". That's extent of my engine vacuum system BTW).
> 
> Was hoping for a coil operated valve but got a solenoid. Oh well, 
what
> do you expect for $5. Next time intake manifold is off will attach
> ground wire to thermal switch in coolant pipe. Until then is 
triggered
> by a switch under the dash left over from earlier experiments. 12v
> supply is taken from old idle speed motor harness.
> 
> Couldn't be happier with performance of this low tech idle speed
> system. Removes all the gremlins that plagued my automatic motor.
> Total investment: $20.
> 
> Anyone want to buy a surplus idle speed motor and ECU?
> 
> Bill Robertson
> #5939