Mike
I have a used dist I could loan, sell you but you need to get out the timing
light and see whats what
someone has to get a look at the timing marks as the critter is misbehaving
timing lights are cheaper than paying the tech to once again tell you he
does not know
timing light sears $30

Bob Donalds

----- Original Message -----
From: "Michael Diehr" <md03@XOCHI.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, January 21, 2007 2:07 PM
Subject: Re: Ping/Knock/Detonation

> First, let me say thank you all for your fast & detailed responses.
> It's such a pleasure reading that it almost makes one want to make up
> phony vanagon symptoms just to see your minds at work.  :-)
>
> After reading these responses, a bell has been rung -- my 1.9 (now
> 2.1 but still digijet) is pinging, but it also has been plagued by
> the hunting idle problem.   What's very weird is that both the
> pinging and hunting idle seem to come & go -- I'll run for a few
> hours and it'll be fine, and then after a long freeway run I'll pull
> into a gas station, and maybe once time out of 4 the idle will be up
> around 1500 & surging.  Usually fine after filling up and restarting
> the engine.  Drive a few more hours, stop for gas, and the idle will
> not be high.   Very odd.   The pinging is also intermittent, though
> with varying road noise, temperature and altitude changes it's hard
> to say.
>
> It almost sounds like I have intermittent weak distributor
> centrifugal advance springs syndrome?
>
>
> On Jan 21, 2007, at 8:05 AM, Dennis Haynes wrote:
>
> > Bob,
> > The VW fuel pump is roller cell pump, no vanes. For most part wear
> > is non
> > existent and it either works or it doesn't. Corrosion on the
> > rollers or
> > outer housing can be the pumps demise. Debris can cause intermittent
> > operation and a bad motor can cause poor pump output. Most pump
> > failures are
> > due to running dry, blocked inlets or debris. On the 1.9
> > distributors I have
> > seen the diaphragms go bad and weak centrifugal advance springs.
> > Bad springs
> > can make real havoc with the idle settings as anything above 900
> > rpm will
> > cause the timing to advance, further increasing the idle speed,
> > then at 1300
> > rpm the fuel cut out occurs, speeds falls, fuel turns back on but
> > O2 sensor
> > is ignored for 30 crank revolutions, so rich mixture, idle speed
> > creep up,
> > ignition advances again, more idle speed, 1,300 cut off. Yes, this
> > is the
> > famous 1.9 idle surge.  It can also add to engine ping as the
> > advance is not
> > where it should be.
> >
> > Dennis
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
> > Behalf Of
> > Bob Donalds
> > Sent: Saturday, January 20, 2007 10:27 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Re: Ping/Knock/Detonation
> >
> >         Its an interseting combinations of events. I guess an
> > extented road
> > trip gives you the time to notice variations.
> > The 1.9 dist has both vac advance, retard plus centrifical advance.
> > Most
> > check the timing at idle and asuume the rest
> > is ok but total advance is even more important to engine life,
> > power and
> > ping than where it is at idle. You mentioned that you went with a
> > rebuilt
> > dist, rebuilt distributors have a better chance of sticking
> > centrifical
> > weights than the old fathful units that came out IMHO. Rebuilts
> > have been
> > washed and lubed maybe once so they easly stick from lack of
> > mantanance.
> > Mantanace? on a dist ? yes my friend right here in river city with
> > the rotor
> > removed on the 1.9 dist you will see a felt pad inside the shaft it
> > requires
> > a drop or two of 3 in 1 oil a couple of times a year to keep the
> > weights
> > lubed and free just like the world famous 009 bug dist plus very
> > other dist
> > installed in a bug from 1971 on.
> > To little advance can be just a leaking vac hose they do rot out
> > and or fall
> > off. That reminds me that my 84 with a 2.1 thas a tee fitting that
> > goes to
> > both the fuel pressure reg and the vac canister from the plentum.
> > If it was
> > not 20 F and dark I might go check that on my own van.
> > The other possiblity that comes to mind is the fuel pump just like the
> > timing its most often checked at idle and pronounced healthy. The
> > vaines in
> > the pump can wear over time 20 years in some cases and idle
> > pressure is not
> > an indication of that the pump is doing under load with the
> > injectors wide
> > open so to speak. Old weak pumps might only have 20 pds at 3K under
> > load and
> > would show some loss just by reving the engine. lower fuel pressure
> > sure
> > would cause a leaner mixture and ping.
> > I also seem to recall that when I first installed my 2.1 engine it
> > ran very
> > lean untill I checked the continuity of the ground wire on the left
> > head
> > from the coolant temp sensor the wire and connector looked just
> > fine but
> > zero continuity.
> > As for timing the 2.1 engine I found 2 things 10 hp more power on a
> > dyno
> > once you get to 3 or 4 BTDC. Number 2 problem you run into a higher
> > idle
> > than desirable made worse by the fact that the engine speed screw will
> > bottom out long before the ilde comes down to a resonable 950 or so.
> >
> > My conclusions
> > 1) Check timing both at an idle and at 3K is best.  When reved it
> > should
> > total about 54 deg
> > 2) TDC is a good place to set the timing on a 2.1 with the digijet
> > system
> > 3) Never trust a dyno reading to tell you where to set the timing
> > (this from
> > the school of hard knocks)
> > 4) check the fuel pump pressure at idle and at 2k
> > 5) checking the exhaust gas with a 4 gas anilizer again at and
> > above idle
> > can tell you lots about the injection system.
> >    Another option would be a fuel air ratio meter with the wide
> > band 02
> > sensor $300   ( how many hours labor is $300 at your local repair
> > shop )
> > 6) very few repair shops do the pin testing needed to see what the
> > computer
> > is getting from the sensors threw the wiring harness AND blame the dam
> > rebuilder for a sh--ty job "must be the cam is in wrong send it back"
> > 7) Ranting seeping in it is past the cocktail hour
> > 8) my spell check does not work
> > 9) Always carry a trash bag in your van and only you can prevent
> > forest
> > fires
> >
> >  going faster miles an hour with the radio on
> >
> > I remain
> > Bob Donalds
> > Boston Engine
> >
> > all rights reserved
> >
> > ----- Original Message -----
> > From: "Michael Diehr" <md03@XOCHI.COM>
> > To: <vanagon@GERRY.VANAGON.COM>
> > Sent: Saturday, January 20, 2007 1:02 PM
> > Subject: Ping/Knock/Detonation
> >
> >
> >> I'm finishing up a long (3K miles) road trip and the van has been
> >> running like a champ (for the first time ever, wahoo!).   However,
> >> I've noticed a problem with pinging (aka knock aka detonation).
> >> It's very particular -- it only happens at 1/2 throttle or higher at
> >> 3200 thru 3500 rpm, even on 91 or 92 octane gas.   Happens most of
> >> the time -- only exception seems to be at temperatures of 30F and
> >> lower at 3000F altitude or higher, which seems very consistent with
> >> it being ping (heat & pressure related).
> >>
> >> As far as I know, the timing of the engine is good at idle, but I
> >> doubt that the advance has ever been tested.
> >>
> >> This is a 85 westy automatic with a newly rebuilt 2.1L block
> >> installed (about 5k miles post rebuild).  It has the stock 1.9FI
> >> system, including a rebuilt computer & distributor & afm.
> >>
> >> It seems weird to me that the RPM range is so specific -- it really
> >> only does it at that particular RPM range.  Any ideas?   Bad
> >> distributor advance?   Flat spot in the AFM?   1.9L FI system not
> >> well matched to a 2.1L block?