Timing advice

I get the principal of setting the timing, but not having done it before I'm after some advice.

For info, engine is a '79 2.0L FI with VW electronic ignition.

Engine has felt a bit.... Lumpy the last few weeks.

I found two vac type pipes that were disconnected but plugging them in made no difference.

So thought I'd check timing.

On a cold(ish) engine it's showing 4 degrees ATDC.

However as I'm typing this I'm remembering that this is with vac still attached.......

Am I right in thinking that it should be 7.5 BTDC?

Here's a video to make sure I'm reading it right.

 

Yep 7.5btdc with the vac lines off the dizzy and plugged too

 

Can I just check that ATDC is to the right, and BTDC is to the left?
It's all in German! Haha

And am I plugging off the vac can on the dizzy, or the hose that comes off it?

 

Funny, that ...

 

Clockwise rotation... So to the left is indeed before

 

Vor=before

Nach=after

 

Perfect. Cheers guys. Out at the mo, but does it change much with vac disconnected and plugged?

Coz 4 ATDC is quite a way from 7 BTDC!

 

And should engine be warm or cold?

 

It doesn't matter.

 

The current timing setting is also based on that mark I see being the TDC mark!

Should probably check it is before I start changing the timing!

 

What dizzy have got ?

 

"Standard one".

 

Duel vacuum with electronic ignition, isn't the timing spec on the engine lid ?

 

Never noticed anything on the lid.

I shall brave the rain and go and look (and take a photo).

 

Its not a dual VAC I don't think, is it? Single VAC is 7.5btdc

 

My sticker says this:



Mine is a federal model though where yours is a Californian model so could ve different but i don't think so

 

Good work young man!

Here's the dizzy.
I assume the "dual vacuum" refers to the two lines coming off of the vac can?
Black and greeny one.




Found this on the engine lid too.
Presumably it's the right sticker for the engine!
Explains the 4-5 ATDC though.
So might only need a slight tweak to take it from 4 to 5 ATDC.



Got the timing gun back out and noticed that the strobe wasn't quite constant.
It would go flash, flash, flash, nothing, flash, flash, nothing, nothing, flash, etc.

So thought, I wonder if the lumpiness is due to no spark.
Whipped the dizzy cap and rotor arm off.
Dizzy cap looked quite new (but with marking on the insides).
Rotor arm looked very dirty.
So swapped with the genuine Bosch cap and arm that I had spare.

Started engine.......
Perfect! Smooth as a baby's bottom!
And checked the timing light again... Flash, flash, flash, flash, flash, etc. Constant!
Woop woop.

Dunno if you can tell the difference in these two videos.
One (before) had quite a bad "knocking" sound.





I'm finally getting used to this air cooled engine lark!

Now to sort out the smoking exhaust from the leaking rocker cover!

 

Nice work

 

2nd video sounds sweet , just like mine