Date: Sun, 9 May 2010 14:01:47 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: throttle body fun
Content-Type: text/plain; format=flowed; charset="utf-8"; reply-type=response
hi.
lol,
I don't think it was a waste of time...
just learning the condition of your throttle body was worthwhile.
a concern I have is that a worn TB will prevent consistent return to idle
contact on the switch.
Like half the time it returns when returning to idle it doesn't quite
'reach' and make the switch close properly.
When I adjust 'em, I check about 6 times that ever time the throttle is
released, the switch closes.
I also don't think it ever hurts to lube the throttle body shaft.
bummer about that throttle cable barrel clamp ...you probably won't make
that mistake again !
( I either lay that part aside in the engine compartment, or best..put it in
a container, or even clamp it back on the throttle cable so it can't get
lost. )
speaking of ...the coolest little parts container. I get them at Fred Meyer
stores. $ 250 each.
Small metal can with a clear window top so you can see at a glance what's in
it ...and it's magnetic on the bottom, so it stays put on a metal work
bench. For small parts...about the nicest storage device I've even seen.
on that oil o-ring at the breather tower..
I have the best luck with Toyota black silicone .....
seals for oil or coolant, bare metal-to-metal, or plastic-to-metal ..
even with no gasket or o-ring ...seals perfectly basically forever ..
It's for putting a toyota V-6 engine water pump right to the block, with
that sealant only. I really believe in that stuff,
and I don't believe in any o-rings installed dry *at all* ..
they *always* get hard and brittle, or shrink or whatever ....installing
them dry is a 'theoretical' thing in my world, theoretically they should
seal and last, but they don't.,
I wish the o-rings that were on the Space Shuttle that exploded on launch
had that Toyota stuff on them , no kidding.
'too theoretical engineer stuff like that really gets me ...
in theory it should work, in the real world ..... ( and the engineers on
that one were worried too, about the cold temps ) ...
'stuff happens' and I have seen over and over where an o-ring installed dry
just does not cut it after a few years.
0-rings *always* leak after a few years. Use that silicone, or any very
high quality silicone on them ..no problem, forever basically.
what fun we are having with our vanagons !
Scott
www.turbovans.com
----- Original Message -----
From: "Alistair Bell" <albell@SHAW.CA>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, May 09, 2010 12:07 PM
Subject: throttle body fun
i posted this text plus pics on my blog (http://shufti.wordpress.com/)
Yesterday I decided to take the throttle body off my ’86 syncro (2.1
l), to clean it up and double check the throttle valve position
switch. Well it turned into one of those “why did I do that?”
projects.
I had more than just idle curiosity driving me, the van had been
having occasional lag in standing start acceleration which I thought
might be due to the throttle valve position switch (TVPS), even
though it had been recently adjusted. I was suspicious that the
throttle shaft fit in the throttle body was loose and that might be
affecting the TVPS.
Getting the throttle body off is pretty easy, I did find that the two
bolts holding it onto the plenum were not tight, I wondered if that
had allowed a little air leak? Who knows.
Got the throttle onto the bench and gave it a quick cleaning. Wasn’t
as oil crusted as I had expected, someone must have been in here in
the last few years. The TVPS had a black plastic cover on it, I had
not seen that before. It sure keeps the actual switch nice and clean,
see photos.
The bore and butterfly had wear in them, as expected. The design of
the TB allows axial play and this lets the butterfly rub on the bore.
The pics don’t show it quite as well as I had hoped. But there
didn’t seem to much if any lateral play that would affect the TVPS
setting.
Using a multimeter set on ohms and “beep” for continuity I check
the TVPS setting. it was within spec, but I managed to fine adjust it
to fall between a 0.003″ feeler gauge and 0.002″ shim stock. I was
feeling pretty cocky at that point, and toddled back out the the van
to re-install.
It was then I noticed the little clamp that connects the throttle
cable to the TB was missing, argh. I must have dropped it between the
van and the bench… probably on the gravel driveway. I spent quite a
while searching, with magnet too, but no luck.
So I ended up making a quick and dirty substitute. Mild steel and a
5mm hex socket machine screw. It worked out ok.
I figured I’d blow the entire afternoon and take the crankcase
breather tower off and check the O-ring that seals it to the case.
The O-ring was as hard as hard can be, was it ever soft? It was also
broken. The old ring broke into pieces getting it out. I didn’t have
a replacement in the collection but I had a spare breather tower and
I swiped the O-ring from that.
Cleaned up the oily mess from all the associated hoses, placed some
sections of braided rubber vacuum lines, and put everything back
together.
The van runs pretty well the same, maybe a tad higher idle, will deal
with that later. Needs a few more miles of driving before I admit it
was all a waste of time.
alistair
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