[Vwdiesel] Re: max fuel adjustment

[Nate Wall]

A while back I call Bosch Technical Support and asked
specifically where I could get good hard numbers for
tolerances and performance measurements for specific
injection pump models. I was told that the information
is proprietary and only released to Bosch Authroized
Injection Puump Repair Facilities.

--Nate
--- "William A. Thompson" <twogreek at hotmail.com>
wrote:
> Hmmmm ...
> 
> >"Will Taygan" and "H.Hagar"  wrote in a Thread
> 
> First ... at the bottom was ...
> >I'm going pick up a copy of the bosch ve yellow
> book to see if I can internalize this.
> >Ummmm   good idea.
> 
> 
> I just received the new edition of the Bosch Book on
> our injection pumps from Bentley the other day. The
> old one was out of print when I ordered it months
> ago ... and they just put out a new version. Will
> ... come look at it if you want to ... it is pretty
> good in explaining the theory .. but lacks on
> specifications ... can't take measurement specs from
> the book ... as in it doesn't have 'em ... to
> determine if anything is out of tolerance. No
> measurements, volumes or pressures given except in a
> general sense. I think they might call that
> "proprietary information"? .. ... ... or "effective
> stealorship market positioning?" ... or the .. "bend
> over" position ???!!!
> It does seem to cover the theory of all pumps in the
> VW line. I only have the NAs so I can't begin to
> evaluate it's treatment of the turbo/newer pumps. I
> am still ingesting and reflecting on the theory ...
> really haven't had enough re-reading and
> re-reflection time to best conceptualize it as yet
> ... but I plod on.
> Does anybody know if the old Bosch VE book gave
> specs to evaluate the condition of the pump? How
> about internal adjustments/replacements for springs
> and such? They indicate that the internal parts are
> not interchangeable ... is such the case in the real
> world as to cannibalism? Any insight as to what a
> good authorized rebuilder can actually do?
> 
> 
> >Ummmm...
> >Is this right?
> >Top of pump (screws connected to accelerator)
> controls the amount of
> >fuel injected, thereby controlling idle and max
> rpm.
> >Ummmm     not really.
> 
> I agree Hagar ... to the extent that I see the
> statement as correct as far as it goes ... but
> possibly misleading without context. All these
> adjustments affect the others and ... depending on
> how you look at it .. and the point in the process
> of adjustment that is being discussed .. the
> statement itself can't be judged without the context
> that is understood by the time this statement can be
> made and be valid.
> By the time one gets to the point of final
> adjustment ... while making the top screw
> adjustments one could look at it this way in a sense
> ... and be effecting a fine tuning of low and max
> rpm as the final adjustments in the process.
> 
> 
> >Side of pump controls max fuel given at a
> particular degree (of the top of pump accelerator
> control), in
> >essence giving more fuel for the idle, more fuel
> for the mid range and more fuel for max at a given
> rpm,
> >(raising the scale).
> >Ummmm   not really.
> 
> Again I agree/disagree with the statement depending
> on the context. All the adjustments affect one
> another and all ... within the scope of their
> function/influence ... control the volume of fuel
> delivery for each gulp of fuel within the scope of
> their influence.
> So far my take on it is that ...
> To make the concept of the statements be more
> descriptive of what is going on ... isn't it more
> like ... load creates demand which the pump responds
> to by supplying more fuel. The full load screw on
> the side is adjusted for how much fuel is being
> dumped in according to load demand thru the rpm
> range ... while the top screws are then used to
> limit the rpm range by limiting fuel volume at their
> "end of the scale" point of influence.
> 
> It was kinda funny how my head got a little dizzy as
> I had to make the effort to change perspective while
> reading with tri-focals ... from carburetors and how
> they mostly use vacume to respond to load then use
> centrifugal force to respond to rpm ... and
> injection pumps using centrifugal force balanced
> against springs to respond to load then use pressure
> within the pump to respond to rpm. Likewise all of
> these adjustments end up being influenced by all the
> others ... and all are responding ultimately to
> load.
> But it seems that ... at it's most basic description
> ... the full load screw on the side adjusts the
> volume of fuel delivered thru the rpm range and the
> two top screws then adjust the limits of the rpm
> range.
> 
> >PS:   My version on the way.
> 
> Yes ... Reality check appreciated ... please Hagar
> ... you other wizards too ... 
> 
> Bill
> Sedro Woolley, Washington.
> _______________________________________________
> Vwdiesel mailing list
> Vwdiesel at vwfans.com
> http://www.audifans.com/mailman/listinfo/vwdiesel


__________________________________
Do you Yahoo!?
Yahoo! Small Business $15K Web Design Giveaway 
http://promotions.yahoo.com/design_giveaway/