[DML] Re: New here (Choke Plates)

["content22207" <brobertson@xxxxxxxxxxxx>]

Actually, a choke is a restrictive plate that physically prevents air
from entering the engine (kind of like a throttle plate). You find
them on carburetors, not fuel injection, because of the way
carburetors work. Their purpose is to keep manifold pressure higher
than normal even as the throttle plates open so that more fuel than
normal is pulled into the engine. Fuel injection accomplishes the same
thing by spraying more fuel than normal through the injectors.

On K Jetronic, this is done via the CPR (Warm Up Regulator). Cold,
throttle plate movement, which correspondingly lowers the air sensor
plate/raises the metering piston, results in richer than normal fuel
metering through reduced counter pressure. As the engine warms up, the
CPR increases counter pressure, bringing fuel metering closer to normal. 

The only purpose of the cold start injector is to provide a momentary
shot of extra fuel during the cranking process. Once started, it has
absolutely no effect on the engine (is no longer spraying). It's
function is actually equivalent to pumping an accelerator pedal
attached to a carburetor (squirting fuel from the accelerator pump),
not a choke plate.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, Greg Zapf <x86Daddy@xxxx> wrote:
> My car had a "choke" installed by the PO to get it to cold start by
> manually activating the cold start valve with a push button.... 
> thankfully, their hack was easily reversable after figuring out the
> culprit:  The Control Pressure / Warm Up Regulator.  This tech article
> describes the diagnosis and fix:
> http://dmcnews.com/Techsection/controlpressreg.htm
> 
> If you have difficult cold start, but once warm, it runs fine and
> restarts fine, this could be the culprit, and it's a quick, cheap fix.
>  (you'll need to get replacement copper washers in advance though)
> 
> --Greg
> #2894
> 







To address comments privately to the moderating team, please address:
moderators@xxxxxxxxxxx

For more info on the list, tech articles, cars for sale see www.dmcnews.com

To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/dmcnews/

<*> To unsubscribe from this group, send an email to:
    dmcnews-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/