Re: Fuel Counter Pressure on Bosch K-Jetronic

["content22207" <brobertson@xxxx>]

Actually counter pressure is controlled by the CPR. Bosch makes many
different CPR's that could bolt right up to the PRV, identified by the
last 3 digits in the part number (the ones stamped rather than cast
into the upper housing). Some exert more counter pressure than others,
or have a longer warm up curve. Not all have full throttle enrichment.
Check out John Hervey's CPR page (unfortunately no spec's):

http://www.specialtauto.com/delorean-parts/warm-up-regulators.html

Another List member is currently running with my spare 038 series CPR
in lieu of his failing 066 series, no problems. It has lower final
counter pressure, and takes longer to warm up, giving him a generally
richer mixture (CO2 screw was leaned accordingly). Full throttle
enrichment is much less complicated than 066 series (one vacuum line
that simply tugs on the internal diaphragm at partial throttle).

I'd recommend finding a CPR with necessary specs.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, Marc Levy <malevy_nj@xxxx> wrote:
> The idea that " boosts fuel pressure causing more fuel
> to be injected based on the same signals" may be
> correct on more modern MPFI systems, but I do NOT
> believe this to be true on our Bosch systems.
> 
> There is no "signal" for fuel. The fuel is regulated
> by a mechanical valve which is controlled by air
> pushing down on a large disk.