Fuel Distributor Differences between CIS-E('85-87 4kq 5 cyl K X) & CIS-EIII(post '87 5cyl NG)

[Dupree, Jim]

They are different! The CIS-E III system is what Audi referred to as 'High
pressure concept'. The fuel pressures in the system went up significantly.
The system pressure jumped to 6.1 - 6.5 bar (88.5 - 94psi), CIS-E was 5.2 -
5.6 bar (75 - 82 psi). The fuel line connections are different and the
injectors are also different in their pressure range and threaded fittings.
You are stuck using the CIS-E III system complete.
You may even have mixture problems with the CIS-E III fuel distributor on
the CIS-E airflow sensor housing. I don't know this for sure but I ran
across a VW rabbit that had a slightly different housing and it ran way too
rich except at idle. The diameter of the airflow sensor plate and the taper
of the cone in the housing affect how high and how fast the sensor plate
lifts for a given air flow. These have to match the fuel distributor
characteristics.
I have my own 2.3L transplant under way for my 4kq and I am planning on
using the complete system from the fuel line connections (supply and return)
in the engine compartment all the way to the injectors. I also have a
complete (almost) donor car. And as I was looking up the fuel pressures for
the e-mail I realized I probable have to swap the fuel pumps as well. I
don't know if the 4kq pump can handle the higher system pressure long term.
Too bad the pump is not very old :(
Good luck and keep us up to date.

Jim

 -----Original Message-----
From: 	Huw Powell [mailto:audi at mediaone.net]
Sent:	Wednesday, February 13, 2002 4:41 PM
To:	bswann at worldnet.att.net
Cc:	'quattro at audifans.com'
Subject:	Re: Fuel Distributor Differences between CIS-E('85-87 4kq 5
cyl KX) &  CIS-EIII(post '87 5cyl NG)

My "gut" is the same on that.  According to Probst, as I recall, CISE
and E3 are identical fueling systems, the E3 incorporates the knock
sensing ignition system as part of the engine management - and it is
usually a separate, stand alone module on these engines anyway.

There is a slight difference, which makes mix and matching components
*within* the systems iffy - the E3 control pressure reg. is set up to
vary around 0 mA, versus the E at 10 mA.  This provides, I suppose, a
better "limp home" mode, but does mean that the computer and at least
the CPR are different.

If I were you I'd use the "already in the car" system, tack on the NG
fuel lines if you have the two piece manifold, and hook up the E3
ignition system at the same time.

The only interface between the fuel & ignition systems on CISE3 seemed
to be one that allowed the ignition system to pass along the "full
retard" signal to the fuel computer so it could display a warning light
on the OBD thing, when Marc and I were trying to figure it out.

Another note, is that when I dismantled my wrecked 90Q for storage, the
ignition system did come out as a discrete system.  Along with about 12
other harnesses... an entire 2 cu ft box full of wiring!

Ben Swann wrote:
>
> Today's question: Regarding the install of complete NG  setup into 4000Q -
>
> Are there any differences I should be concerned about between the CIS-E on
> a '85 4000 Quattro and the NG CIS-E setup - in this case from a 87.5 GT
> Coupe?  I have both, but they appear identical.  I'd hate to go through
the
> trouble of swapping the fuel distributor head if there is no difference.
>
> The fuel distributor came with the NG engine but I didn't get anything
> below that, so I'd have to swap with the airflow sensor plate assembly
> below on the 4000 if I need to.  Id hate to take apart any more than
> necessary, however and my gut tells me these are the same - they look
> identical.

--
Huw Powell

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

http://www.humanthoughts.org/