CIS, abbreviation for what? (Was: Re: idle speed regulator)

["content22207" <brobertson@xxxx>]

Your misidentification is actually quite common:

CI -- "Continuous Injection"
CIS -- "Constant Idle Speed"

These are Bosch's terms, adopted by Peugot, Renault, and Volvo.

Fuel injection actually occurs right before the intake valves. Those
are the injectors adjacent to the spark plugs. The circuitous air
route before then is simply to build up velocity. Note that the
driver's side intake rail feeds passenger side cylinders #1-#3, and
vice versa.

You are absolutely correct that all 6 injectors spray continuously,
whether or not an intake valve is open to receive the mixture. That's
the beauty of K-Jetronic -- very simple, with very few moving parts to
malfunction. The fuel distributor only has one part that moves a lot
(metering piston) and one part that moves very little (primary
pressure regulator). That's it! Ages quite well, especially given the
limited road time many DeLoreans are exposed to.

Note also that CI is nearly 100% mechanical. Disregarding Lambda
(which was NOT part of the original design), the only essential
electrical component is the fuel pump (the CPR will gradually warm up
from ambient engine heat alone, even if unplugged -- that's why it is
located where it is). Again, very simple with few electrical parts to
malfunction.

I am an old timer who grew up with "simple" carburetors. Was very
adverse to anything "fuel infected" (actually a term coined by my best
buddy). One of the primary reasons I travelled all the way to
Pennsylvania to purchase my particular DeLo was the PO promised a
carbureted re-engine. He was wrong of course, and I have since learned
to appreciate the Bosch system as implemented on our cars. I am still
adverse to ELECTRONIC fuel injection, but its mechanical predecessor
is more than satisfactory to me now.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, Jan van de Wouw <delorean@xxxx> wrote:
> On Tue, 20 Jan 2004 17:23:30 -0000, Bill Robertson wrote:
> 
> > CIS (Constant Idle Speed) system has been covered before
> 
> Could be me, but I thought CIS was for
> Constant Injection System

> JAN van de Wouw