CIS3, Javad's opinion...

[JShadzi at aol.com]

See inserted...

> > The E3 module probably just does things all wrong at
> > some points on the
> > curve(s) for a turbocharged engine.

Yes, but you need to qualify this, without the CIS potentiometer, the CIS3 ignition module is virtually unuseable unless this all important load input is addressed and restored.  Once this is done the internal ignition maps can be "easily" manipulated.

Before we get too deep here, let me just say that I've toyed and experimented with the CIS3 ecu for hundreds of hours, only thing I haven't done is to reprogram the eprom inside it.

> > >>One other thing. I still notice the timing is
> > >>bouncing
> > >>around somewhat. I set it to 0 BTC and it stays
> > >>there
> > >>a while but then advances to 15 BTC (this is the
> > >>reason it failed smog the first time I believe).
> > >>Lately it has been doing less of this, maybe the
> > >>ignition computer is learning ??

Ed, if your static timing and tuning is set correctly, and your pot. output is consistent, then there is no reason for CIS3 to wander the timing, it will only do in resonse to what the inputs tell it, which are only throttle switches, temp sensor, potentiometer, knock sensor and hall output -  all in the context of the manually set static timing.

IME, a standard 80 turbo conversion keeping the stock ignition system can run about 6-8 degrees of static advance running premium fuel and no more than 12psi boost.

> > I don't think that unit is capable of learning.

That is correct, but it can do 2 things however, based on knock and temp.  The ECU has within it 2 ignition maps, one for premium fuel and one for standard fuel.  Everytime you start the car it defaults to the prem. fuel map (based on the temp sensor input and ignition restart).  If the knock sensor registers what it considers to be excessive knock (or repeated retard adjustments within a certain amount of time), it will kick back to the regular fuel map which is more retarded.

What could likely be happening in your case is the switch over between the two, and thus the retard you're observing.

>  It
> > does, however, run a
> > lot more advanced off idle than you set it, for what
> > I have observed -
> > set it at, say, 15 DBTDC, and crack the throttle a
> > tiny bit (ie, open
> > the idle switch) and it jumps to something like 45
> > degrees BTDC.
> > probably just what the NF/NG wants, but maybe qwuite
> > wrong for a turbo
> > engine.

This is correct, but pretty much any motor loves a lot of timing advance right off idle (or even at idle for that matter), under cruising and light load (according to the pot. output), timing can be advanced anywhere up to 50 degrees.

> > > You asked what you could do next?  New engine
> > > management my friend, you will not regret it.

Well, yes, this is always an option, but Ed, you've hardly scratched the surface of what you can do, but you're running the CIS too, which will limit you soon enough regardless of ignition.

What I did with my 80tq...the secret to the CIS3 ecu is the pot. input, if you can manipulate this the you can control it.  The CIS3 ecu will determing advance based on a 0-5v load signal, if you can control this then you can effectively program the ecu to whatever advance you like.  I developed a series of electronics to give me control over this.  First off, I regulated a 0-5v supply, this was input into a MAP sensor, and its output was modified by an ECU that we developed that would add or subtract voltage from the MAP output based on a rpm and MAP matrix.  There are several layers of adjustability:  0-5v at the regulator, 1, 2, or 3BAR calibrated outputs for the MAP (the stock 034efi ecu MAP gives a 2.65BAR output)sensor being used, and a + - 2v for the ecu.  This worked very well after a length of development, and I though about offering it as a compliment to the 034efi products, but alas developing the StageII ECU to do distributor or direct fire ignition was the overall goal from the beginning, and is SOOO easy to install and tune with, so out the door CIS3 went.

> >  From what Marc tells me, the "next generation" of
> > 034 will include a
> > tweakable (?) ignition controller, and a driver for
> > some inexpensive GM
> > idle stabiliser valve.  Nice touches both of them, I
> > think.

Yes, this is correct, just finished testing it on my car, I'm very excited.  Currenlty my 034efi Stage II ECU controls all fueling, ignition, tach, fuel pump, and idle stabilization in 80tq, in fact there is no factory system controlling anything related to engine function or measurement... but more about that later in a future post.

Javad