Re: [Fwd: rpm]

[steveb@falcon.kla.com (Steven Buchholz)]

> My warm-up regulator is definitely shot.  The MB engine uses part #034
> 133 403A.  This also has only one vacuum connector, although it's capped
> on my car.  What interests me is that the new one I bought in Berlin
> yesterday morning has an adjustment screw recessed into the face that's
> bolted to the engine block.  The old one doesn't have any adjustment
> there.  Anyway, the "shot" one gives me 6 bar onto the fuel metering
> head and the nominal should be 3.4 - I'll be changing it tomorrow.
> 
... actually there is a little secret about most if not all control 
pressure [aka warm up] regulators.  There is a nondescript metal plug 
on the thing that looks like a casting mark.  You can actually move 
this plug in and out to adjust the control pressure.  It sounds like 
they made it an official [and more precisely set] adjustment on your 
new CPR.  I had a filter meltdown in my Fox after attempting to use 
some injector cleaner so I had to replace the fuel distributor ... I
used Buchholz' law [if it's already f'ed up I can't make it any worse
by taking it apart and trying to fix it] on the CPR and found that it 
is actually quite simple inside.  The only reasons I can see for ever 
needing to buy a new one would be if the heating element opened up or 
the bimetallic strip wasn't working correctly.  

The other secret about this plug is that it is a neat way to help 
richen your mixture ... reducing the control pressure increases the
amount of fuel delivered at a given operating condition.  I'm not sure 
if I read about the CPR in Greg Raven's VW book or if it was one of the
Bosch books on the _-jetronic ...

Steve Buchholz
s_buchho@kla.com
San Jose, CA (USA)