Home Technical Discussions Volkswagen Vanagon: 1980-1991 (T3)

Volkswagen Vanagon: 1980-1991 (T3) Ignition Timing


Permlink Replies: 13 - Pages: 1
Last Post: Dec 6, 2005 5:39 PM Last Post By: DaveDailey
TallyRich

Posts: 4
Registered: 07/20/04
Ignition Timing
Posted: Jul 20, 2004 12:30 AM
  Click to reply to this thread Reply
Simple question, but I can't find the information anywhere, including the Bently manual. Which cylinder is number 1 and how do I check the timing. The book shows a notch on the pully and where to line up the mark when setting the timing, but I don't see anything that would tell me when I'm at 5 ATDC.
wohlfarth

Posts: 1,745
Registered: 10/31/03
Re: Ignition Timing
Posted: Jul 20, 2004 10:30 AM   in response to: TallyRich in response to: TallyRich
  Click to reply to this thread Reply
The timing mark information shows up in the beginning of the manual in the Technical Data section.

The identification of the various cylinders is something we added to the manual a few years ago. It shows up at the back of the book (in another techincal data section) on page 27. Let us know if you don't have this in your version of the manual (i.e. an older version).

As for determining where the 5 ATDC is, I would suggest using a strobe timing light with an adjustable dial you can use to determine when you are at the correct timing point. It looks like the 1.9L engine only has a mark for TDC on the pulley. I have one of these adjustable timing lights myself and it is really very handy to have.

Good luck,

Stan Wohlfarth
Bentley Publishers
TallyRich

Posts: 4
Registered: 07/20/04
Re: Ignition Timing
Posted: Jul 20, 2004 12:08 PM   in response to: wohlfarth in response to: wohlfarth
  Click to reply to this thread Reply
Thanks for the help. No, my book doesn't have the additional pages. Since I couldn't sleep anyway last night I perused the book looking for the information. I did see reference to the location of the timing mark and TDC, but the ATDC is the part that I didn't see. I guess the adjustable timing light would be the answer, mine doesn't adjust. I'll try to borrow one and then etch my own mark for future reference.
wohlfarth

Posts: 1,745
Registered: 10/31/03
Re: Ignition Timing
Posted: Aug 2, 2004 11:15 AM   in response to: TallyRich in response to: TallyRich
  Click to reply to this thread Reply
Attachment Vgon block.jpg (56.4 KB)
TallyRich,

I'll attach a picture of the Vanagon engine block and the number of each cylinder.

A lot of us just know this from years of dealing with the 4-cylinder opposed engine (i.e. air-cooled Beetle, Bus, etc.). The order of the cylinders hasn't changed since way back in the 1940's. Unfortunately when the 2.0L air-cooled Vanagon engine evolved into a 1.9L and later 2.1L water-cooled engine, the cooling tin over the cylinder heads also went away. This tin had the cylinder numbers stamped into it. Without the tin there is no easy way to know which cylinder is which.

Let us know how you make out on notching a timing mark.

Stan Wohlfarth
Bentley Publishers
TallyRich

Posts: 4
Registered: 07/20/04
Re: Ignition Timing
Posted: Aug 2, 2004 2:30 PM   in response to: wohlfarth in response to: wohlfarth
  Click to reply to this thread Reply
Thank you, that's a big help. I've had the flat 4's in the past but always just looked for the markings and never really realized that #1 is always in the same place no mater the vintage. I haven't had a chance to borrow another timing light, so I've relied on the "ear" method. My fuel economy has improved.
vanalemon

Posts: 75
Registered: 03/03/04
Re: Ignition Timing
Posted: Aug 5, 2004 11:46 PM   in response to: TallyRich in response to: TallyRich
  Click to reply to this thread Reply
Hello,
an adjustable timing light is probably very handy, but at least conceptually, it seems easy to mark a few interesting angles on the pulleys.

If you take a measuring tape (ikea has the free paper measuring tapes :) ) and measure the circumference of one of the pulleys, you just have to mark a notch at an "arc" proportional to the angle.

Example, say the small pulley has a measured circumference of 565mm (I am *assuming* a diameter of 180mm).
If you want to mark 5 degrees, measure a distance along the circumference (an arc) of length (5/360) times 565mm= 565/72 = 7.8 mm

Just as a note, if you use the largest pulley you get more accurate results, but the timing angle is probably rough anyway.

Hope this makes sense to everyone,
Claudio
TallyRich

Posts: 4
Registered: 07/20/04
Re: Ignition Timing
Posted: Aug 6, 2004 12:13 PM   in response to: vanalemon in response to: vanalemon
  Click to reply to this thread Reply
Excellent suggestion. I always tend toward the technical answer (especially when it gets me new tools) This is a great and practical answer. I'll do this while on vacation.
vanalemon

Posts: 75
Registered: 03/03/04
Re: Ignition Timing
Posted: Aug 28, 2004 4:10 PM   in response to: TallyRich in response to: TallyRich
  Click to reply to this thread Reply
Hello,
I just ran into a page in the manual that is somewhat related.

At page 13.34 it shows a 1986 water-cooled engine.
In particular it shows the various pulleys, and for one of them it mentions that the replacement part only has the TDC marking and not the 5 degree notch.
It then suggests to add this notch at 7.5mm to the right of the TDC notch.

Funny how close I was my estimate :)

Claudio
DaveDailey

Posts: 11
Registered: 11/12/05
Re: Ignition Timing
Posted: Nov 12, 2005 6:03 PM   in response to: vanalemon in response to: vanalemon
  Click to reply to this thread Reply
delete

Message was edited by: DaveDailey

DaveDailey

Posts: 11
Registered: 11/12/05
Re: Ignition Timing
Posted: Nov 12, 2005 6:12 PM   in response to: wohlfarth in response to: wohlfarth
  Click to reply to this thread Reply
delete

Message was edited by: DaveDailey

DaveDailey

Posts: 11
Registered: 11/12/05
Re: Ignition Timing
Posted: Nov 12, 2005 8:49 PM   in response to: wohlfarth in response to: wohlfarth
  Click to reply to this thread Reply
Sure enough, your diagram show cylinder three, where I have cylinder one. I timed off your three... PERFECT.

Thanks, pulled*hard* on rotor with extra large channel locks. got it off.. good. but on next trip, van ran hot, with extra power up hill. timing was off. I had advanced the timing a few degrees...twisting the rotor pulling it off. BE CAREFUL pulling them off. My timing pulley had notch exactly in right place to time, with edge of vertical engine case casting seam fin. 12 oclock to 12 oclock. 1990 GL westfalia.

My TDC notch was actually 5 degrees or whatever, BTDC.

I tried AFTER TDC, ran - no power. tried BEFORE TDC, ran hot, fast. Then tried with notch at 12 o'clock position right in line with engine case seam, 12 o'clock to 12 o'clock... PERFECT.

1990 GL Westfalia
DaveDailey

Posts: 11
Registered: 11/12/05
Re: Ignition Timing
Posted: Nov 13, 2005 10:20 AM   in response to: vanalemon in response to: vanalemon
  Click to reply to this thread Reply
delete

Message was edited by: DaveDailey

DaveDailey

Posts: 11
Registered: 11/12/05
Re: Ignition Timing
Posted: Nov 16, 2005 1:05 AM   in response to: DaveDailey in response to: DaveDailey
  Click to reply to this thread Reply
Actually- I have been VERY carefully reading Bentley... most of my erros occurred due to looking in the engine rebuild digifant section, and seeing contradictions with the normal digifant section (1990 Westy). My pulley has both a notch (5' BTDC) and u-groove (for TDC). I found one spot in Bentley that says the notches are 7.5 mm apart. True. If in a rebuild, you must mark a new pulley with the notch, 5' BTDC, 7.5 mm to the right.

Voila... all problems solved. Now on the solving fast idle.....
DaveDailey

Posts: 11
Registered: 11/12/05
Re: Ignition Timing
Posted: Dec 6, 2005 5:39 PM   in response to: DaveDailey in response to: DaveDailey
  Click to reply to this thread Reply
deleted

Message was edited by: DaveDailey


Point your RSS reader here for a feed of the latest messages in all forums

Popular Discussions:
No popular dicussions.