Idiots guide to setting timing/Auto distributor

[Sir Brixalot]

So far I have found tdc and attached the strobe to the spark plug RH side at the back. How do I set it at 8 degrees btdc at idle which is meant to be the sweet spot. The simpler the description the better please

[itchyfeet]

disconnect dizzy vac
loosen pinchbolt and preferably with rubber gloves tirn dizzy until right
then tighten bolt
if your gun has adjustable angl set it and use tdc marker
if your gun does not you will need to mark the angle on the pulley on the right side of tdc
use tippex to highlight marks
7mm around a dg single pulley is 5 degrees

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[Sir Brixalot]

Thanks Mr I. Think i've done it right. When I put the vacuum lead back on the mark goes to around 30 btdc though. Is this expected?

When I blow though the pipe I can hear a very faint "pop".

[itchyfeet]

mmm not sure about that sounds alot
readthis

https://club8090.co.uk/wiki/Pe ... nce_curves" onclick="window.open(this.href);return false;

which way are you blowing

[kevtherev]

Thanks Mr I. Think i've done it right. When I put the vacuum lead back on the mark goes to around 30 btdc though. Is this expected?

When I blow though the pipe I can hear a very faint "pop".

no that's not right.
When vacuum is back on you should only get 1-2 - deg advance.
without vacuum max advance is 28 deg.
says to me your mechanical advance spring is busted or are not connected

[Sir Brixalot]

Will go and have a look at it

[Sir Brixalot]

Right it makes more sense now, I should have been sucking. I sucked on the vacuum advance nipple and there is movement of a few mm in the lever an in the distributor. Did the timing again at 5 btdc put the vacuum hose back on and it shot up again by 2O degrees. Think I'm going to have to go to a garage but I'll watch so I know exactly what to look for if it happens again.

[bigherb]

Is the vacuum pipe on the correct connection on the carb? It should be on the one to the left of the vehicle.

[Sir Brixalot]

Yes its on the LH side. The garage was closing as I arrived but the mechanic who only does old VWs asked if the dizzy was dry. Its as dry as a bone, so that could be it. I've never thought of lubrcating it. I've only got diesel oil at the moment so will have to wait til tomorrrow.

[bigherb]

The oil pad lubricates the centrifugal advance. If the vac advance is moving too much then it is not seized. Check the small hole in the throttle butterfly above the vacuum ports is not blocked or partially blocked.

[Sir Brixalot]

I'm looking at the throttle butterfly(the flap inside the carburettor?) Is the little hole that might need cleaning underneath it? If its the hole in the brass right at the bottom underneath the butterfly then it is clear

[bigherb]

This one

[Sir Brixalot]

Thanks that's great, I'm on a steep learning curve - looking at the hole it looks clear. Jiggled a pin in as far as I could reach to make sure. Going back to the vacuum advance it has to be sucked very hard to get the lever to move - is that normal.

While I'm trying to sort this out is it OK to set the timing with the vacuum advance pipe fitted?

[kevtherev]

Thanks that's great, I'm on a steep learning curve - looking at the hole it looks clear. Jiggled a pin in as far as I could reach to make sure. Going back to the vacuum advance it has to be sucked very hard to get the lever to move - is that normal.

While I'm trying to sort this out is it OK to set the timing with the vacuum advance pipe fitted?

Yes thats normal.
The vacuum will only advance it 16 -18 deg
But the mechanical advance will move the spark 30 deg.
Did you look at the diagram itchy feet posted a link to?

There shpuld be NO mechanical advance at 800 rpm

[kevtherev]

While I'm trying to sort this out is it OK to set the timing with the vacuum advance pipe fitted?

not really