[Vwdiesel] Matt's tach venting time...

mark shepherd mark at shepher.fsnet.co.uk
Sun Feb 15 13:36:01 PST 2009

How sad.
Strange how the cover would hit the  sprocket because of the 6mm bolt. Are 
there not 3 or 4 clips also?
Sounds like at 4000rpm one of you add ons fell off due to the vibration, 
joggled round the timing belt area and went under the belt suddenly allowing 
the belt to jump and mess up your timing. That was the one weakness of 
Roger's great idea. That is why either making a 'W' terminal is better if 
you happen to have a diesel tach, and supplement the terminal with a 
directly modded circuit for a gasser tach. [As designed by Cheesman for a 
few bucks equiv.] As long as alt. belt is not slipping, I've found tach 
accurate at all speeds. Belt screeches and you can see revs drop off... 
Can't say that I've run this engine on my Quantum much over 3.5k
B4 I got a tach on my first TDdiesel Q I admit I did on occasion go over 
105mph.  Too many speed cameras over here to get away with it for long.


----- Original Message ----- 
From: "Matt" <matt_lisa at sprynet.com>
To: "mailing list" <vwdiesel at vwfans.com>
Sent: Sunday, February 15, 2009 8:48 PM
Subject: [Vwdiesel] Matt's tach venting time...

> This was a message I sent to the list on Thursday, though it didn't go
> through since it was down.  I've talked to Loren a bit about my
> problem, but I figured more brains on the problem couldn't hurt.
> ______________
> Hey everyone.  So I got my diesel Rabbit tach all set up and working
> using Roger Brown's optical pickup wheel design.  It was beautiful.  A
> working rev counter in that old car.  Talk about neat.
> So I buttoned it all up and took it for a spin.  It was working
> perfectly, when all of a sudden, the tach went dead.  I wondered what
> the hell was going on, so I started to drive home.  On the way home,
> the car started to buck and kick.  Soon, it would barely run.  I
> hobbled home, and killed the car.  Smoke started pouring out the
> tailpipe.  Now I'm really nervous.
> I pushed the car in the garage and took stock of the situation.  The
> front bolt on the timing belt cover had come undone.  Because of that,
> the cover tipped against the injection pump pulley wheel, taking the
> tach optical sensor clean off.  That explains why the tach died.
> There was oil all over the outside of the valve cover.  I hate those
> stupid cork valve cover gaskets.
> I'm hoping the sensor didn't go flying down into the lower belt
> cover.  Looks like I get to pull it apart and have a looksee.  I'm
> still not sure why the car was trying to die.  that doesn't make much
> sense.
> I had the power for the tach converter hooked to the stop solenoid.  I
> figured the car was bucking because it was coming loose or something,
> but when I popped the hood, all was tight.
> It's times like these, I just wanna sell the car and make it someone
> else's problem.  I'll probably just let it sit for awhile, and then
> have a look.  What really makes me nervous, is the smoke smelled like
> coolant.  I've only got 4K miles on this head gasket.  I was at around
> 4K rpm when the tach stopped working.  With my luck, it blew something
> big time.
> So, anyway, there's my situation.  My Rabbit is currently in the
> garage, cooling off.  After I cool off, I'll start pulling it apart
> and try to find out what the hell happened.  I'll keep everyone
> informed.
> A really bummed and pissed off Matt
> http://matt_lisa.home.sprynet.com/
> _______________
> I tried restarting the car the following day, and it would fire and
> die over and over.  It spewed lots of black smoke when it tried.  So
> far I've checked the timing which seemed off, so I'm in the middle of
> trying to get that adjusted (thought it's being more of a pain than
> normal.)  Any other ideas?
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> Vwdiesel at vwfans.com
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