Any CIS-E III experts?

[Eric S]

Ben Swann said:
> CIS-E is NOT knock sensing - that is one of the major differences.
> CIS-EIII has knock sensing.

Incorrect.  CIS-E can have knock sensing ignition.  Pull up a 86-88
Scirocco 16v in your favorite parts program and check it out.  That is
CIS-E with knock sensing ignition.  According to ETKA, CIS-E3 also uses a
separate control unit for knock sensing ignition...IE, not integrated into
the ECU.

Now remember, we are talking fuel system here, it was used on many
different cars....I'm just letting you know that yes, CIS-E was used with
a knock sensing ignition on all the VWs that got CIS-E.  So lets just
kinda drop that argument, since it seems that CIS-E3, like CIS-E, are
purely fuel control devices.

> Several other differences include:
>
> Wider range  of DPR actuating current - +10mA  to -10 mA with nominal with
> CO adjusting point at 0mA - insures better operation if an electrical
> failure to the Fuel ECU should occur - that would be the "fail-safe" mode
> of operation.  I know from experience that this works, as when I was
> hooking things up, the positive to the ECU became disconnected and the
> engine still ran OK.  Just did not do nice things like operate the cold
> start injector.

Interesting...ETKA does show different part numbers for the DPRs, however,
as an example, lets take a 88 Scirocco 16v (engine code PL):  You adjust
the DPR in the same manner, and it has identical +10/-10 range.  The PL
used CIS-E.

A side note here, CIS-E Motronic uses the identical DPR as CIS-E3. CIS-E
Motoronic was used on the 2.0 16v engines in Jettas and Golfs ~1990-1992
(engine code 9A).

> Higher fuel pressure/flow rate - different pressure regulator, fuel pump
> and accumulator, lines designed for higher pressure.  Lines/fittings are
> not interchangeable nor are the
>
> Higher pressure injectors - opening pressure of injectors is higher using
> different fittings

Agreed, those are different.  More parts however that are the same ones
used on CIS-E Motronic (kinda nice considering I have some spare 2.0 16v
injection parts laying around).

> Fault memory - does not retain faults after ignition turned off

Yep.

> Ignition coil with power stage - higher spark voltage signal from Hall is
> controlled thrugh ECU then amplified prior to coil

Yes, that Hitatchi coil is an interesting one.

> Ignition distributor has no vacuum advance - advance is electronically
> controlled

?!?  As were all CIS-E and CIS-E Motronic 16vs.  No difference there. 
Again, getting into ignition control, which we have established as a
separate system on CIS-E and CIS-E3.

> ISV control in both directions

That I cannot confirm or deny.

> Different coolant temp sensor

Yep

> And the Air sensor potentiometer is different  and not easily  removeable
> as you have found.

Unfortunately here, ETKA won't give you the part number for the actual pot
itself...only the whole plate.  Which is of course different during my
comparison run through the part numbers this morning.  I have a dead CIS-E
Motronic one on my bench, when I replace the one in the Audi, I'll get a
good look at the part numbers stamped into it and let you know.  CIS-E on
the 1.8 16vs did not have a pot at all btw.

> and probably some other differences not mentioned above.

Probably.  I was a bit too general with my statement.  I have been around
A LOT of different flavors of CIS in my time, CIS-E3 is most closely
compared to CIS-E Motronic in my mind, however, its kinda a middle ground
between CIS-E and CIS-E Motronic, like CIS-E3 was a step in the evolution
from CIS-E to CIS-E Motronic.

> I don't believe that you can simply plug in the CIS-E ECU in place of
> CIS-E3 especially since CIS-E3 uses separate ignition and fuel modules and
> expect it to play.

Yes, I've been told not to bother (I was going to check the pin outs), but
several have already chimed in that the pin outs are far too different for
the simple idea my mechanic had.  (trust me, I am a doubting thomas, hence
why I asked the question here to see if anyone had previous experience
with such an idea).

The fact the modules are seperate actually makes it easier...since thats
how CIS-E with knock sensing was setup anyway.  Moot point though...not
gonna try the "back date".

> You could probably re-wire, but that would be taking a
> step backwards.  I recommend you fix the problem.  CIS-E3 electronics
> should be readily available at a junk-yard.  I have passed up many -
> perhaps with take the time to extract next time.   I may have an extra
> fuel distributor - LMK if you need one.

Thanks Ben.  I do appreciate the offer, another lister has emailed me
privately on the matter and has a tested, known good pot on the way to me
as I type.

-- 
Eric
www.vintagewatercooleds.com

1981 Scirocco S (TDI swap project)
1988 Audi 90 Quattro
1990 Corrado TDI
1991 Cabriolet (2.0 crossflow 8v project)