CIS experts-click here

[Huw Powell]

More thoughts on this.

1. before we go any further, the CISE3 ignition is independetn of the
fuel system.

2. I think you should ditch the fuel ECU - too many dumb things to hook
up to try to fake it into simple runnign the ISV.

3a.  If you could build a solid state "thing" that takes the coil signal
as an input and generates a square wave (we'd have to measure a running
ISV to determine the rough frequency to use) with a variable pulse width
that is inversely proportional to the coil frequency, this would run the
ISV all on its own.  baselines... about a 30% duty cycle for the signal
for a warm engine and 4000 pulses/second.  Cold engine the ISV runs up
to about 70% duty cycle, your device might be quick enough to grab the
"stumbling" cold engine and give it air to that rate while it warms up. 
This device would be turned on by the idle switch.  To duplicat the way
the old ECU ran the ISV you would give the ISV a constant 12v and use
the "device" pulse train to ground the ISV "intermittently."

3b.  bag the ISV.  You already have cold enrichment from your EFI,
andyou can tweak that til its perfect I'm sure.  The other thing you
need to run a cold engine is more air - i would suggest using a good old
Auxiliary Air Valve from a CIS system to bypass the throttle body (same
place as the ISV).  These have an internal heater running on constant
12v, and slowly close as they warm up.   Your idle would not be "rock
solid" with a device like this, and emissions would be affected slightly
due to any fuel/air imbalances while warming up, but it would work.

4.  I don't remember if the CISE3 ign. control also tweaks the idle by
playing with the timing a little bit or not...

Hope this helps!

> > Ok, I am having trouble getting the EFI equipped 80tq to idle.  I am still using the ISV, and even incoporated the idle switch on the throttle body.  The problem I am having is that there is no 12v to the ISV terminal (this is a two wire ISV).  To make sure, I even tested the power to the cold start valve and no 12v there either.  The fuse for the "warm up valve" is not blown, and as far as I know there is no fuse for the ISV...could the CIS ECU have been damaged by the shorting of the throttle switch wires?  What am I missing here...

-- 
Huw Powell

http://www.humanspeakers.com/audi/

http://www.humanthoughts.org/