Ignition timing question : 1.5 JB series engine (78 Rocco)

A few months back, I purchased a 1978 Rocco and I am trying to get it started and running in my spare time so that I can move it and work on it properly at my home.

The car has the 1.5 JB series engine with a carb and auto choke.

The guy I bought it from is a friend and he had owned the car for a long time, although he travelled a lot and his dad 'looked after it' while he was away.

Since his dad became very ill, the car has been standing in a garage for about 5 years.

The engine turns over but does not fire. I've been working through the parts in a logical order, so far I have done the following:

Fuel
Fuel Filter
Fuel Pipes
Fuel Pump
Spark Plugs
Coil
HT Leads
Dizzy Cap
Points
Air Filter.

I didn't touch the carb yet as I was worried that I might damage it (I'm somewhat new to all this, normally I am biker )
Fuel seems to anyway be reaching the cylinders, so for now, I was looking at other possible causes

Someone on FB advised me that the timing might be out, so I have been looking into it a bit ans this is what I found:

I used the following article as best I could
https://vwgolfmk1.org.uk/forum/index.php?page=topicview&type=misc&id=how-to_2%2Fguide-setting-your-cam_2
(some of the photos are blurred out)

And I think I have discovered that the ignition timing is out, but I wanted to ask you guys about it and see what you think.

I rotated the bolt on the end of the timing belt, until the following mark is shown through the flywheel inspection hole:



This type of mark does not agree with anything I found in the haynes manual that I bought on ebay.;
but I wasn't able to find any other marks on the flywheel through the inspection chamber, and using the screwdriver in the spark hole method, the piston for cylinder 1 seems to be at the top so hopefully this is correct (feedback welcome!)

I was hoping to find a degrees before TDC mark (as some models seem to have and the manual shows)
so that I could line up the timing with that, but there does not seem to be one.
I therefore suppose this engine either fires at TDC or the flywheel is not original?

Anyway, carrying on, when the engine is in this position, the position of the distributor arm is the following:



If i understand correctly from the 'how to' thread mentioned earlier, the notch in the distributor (where the arm would go) should be aligned with the small mark on the periphery when the timing is correct.

Is that so?
That being the case, the ignition timing would seem to be approx 135 degrees out?

What would be the best way to deal with this, can I simply unbolt the dizzy, rotate it through 135 degrees and replace it?

Some of the info I've read says that is not possible without lots of other engine parts being removed first.

Thanks for any help.

David
 

https://vwgolfmk1.org.uk/forum/index.php?page=topicview&id=big-block-carb-engines_2%2F1-5-engine-timing

If the car was running previously it's unlikely the timing has gone that far out tbh, need to confirm it's on it's compression stroke with cam lobes pointing upwards on no1 cylinder when piston 1 is at tdc of course 👍

Have you checked the gap on the points?

mark1gls said

Have you checked the gap on the points?

I replaced the points and set the gap.

Your dissy seems to be out but it's hard to tell without the rotor arm fitted.

Remove the metal timing belt cover and check the timing marks, you should have a 1 piece cover on a 1978 car so you will need to losen the alternator belt to get the cover off.

You can remove the plastic cover from the gearbox if you have a big Allen key as it screws out so you see easier the fly wheel, looking at your picture you have just pulled out the bung.

mark1gls said

Your dissy seems to be out but it's hard to tell without the rotor arm fitted.

I omitted the photo with the rotor arm as I was not sure if it is fitted correctly. Here is a photo with it fitted.

Presumably if I simply rotate the dissy cap to position which I believe to be correct and manually hold it there while a friend cranks the car that would tell me if the timing is the problem 

Without removing the inner white cover, you can't tell exactly where the mark is to the finger, and you are limiting the view of the flywheel.

The Cam is lobes up on number one, and the diz rotor should be in the middle of the hash stamp that is the little tick mark on the edge.  

The Cam should have a dimple on the back of it that is even to the valve cover tin.

I never worry about the pulley marks as you can rotate the Intermediate pulley and get the dis to where it is supposed to be.  Yes marks are great thing with new, and keeping them that way but over the years and previous owners you never know how they are really.

That is very useful info, thanks a lot.

Do I understand correctly that the intermediate pulley controls dissy arm

i.e. no need to remove the dissy to change the ignition timing, I can simply rotate the intermediate pulley by hand?

David

 

rabbitson said

That is very useful info, thanks a lot.

Do I understand correctly that the intermediate pulley controls dissy arm

i.e. no need to remove the dissy to change the ignition timing, I can simply rotate the intermediate pulley by hand?

David

 

Yes the intermediate shaft spins the Dizzy and the oil pump…. rotating it independently can align the marks just fine.

Excellent tip.

Maybe that also explains how it came to be wrong in the first place if someone replaced the timing belt without considering that.

I'll try that next, fingers crossed.

Thanks a million!

You should be able to see the timing marks on the cog driven by the cambelt so have you removed the cover and checked yet?

You may be able to twist the dissy enough to get the car car running as it is at them moment  but it's worth setting it up properly as next time someone changes the timing belt the timing and sets the engine by the book the timing will be way off again.

Have you also double checked the HT leads order? No1 cylinder (cam belt end of the engine) should be where the line is on the dissy casting then going clockwise it's 1342, when the timing belt marks are set no.1 is around 12 o'clock..

   Once you get it running get rid of the points and condenser and upgrade to electronic ignition, I fitted a Accuspark kit to my 1978 Mk1 Scirocco a few years ago and very pleased with it.
The quality of new points and condensers are rubbish and they don't seem to last very long before they start to fail..

More info here..
https://vwgolfmk1.org.uk/forum/index.php?page=topicview&type=misc&id=electrics_2%2Felectronic-ignition_16

Removed the alternator, timing belt cover and loosened the timing belt.

Then I positioned the dissy using the oil pump/dissy cog to the specified position and the beast fired almost immediately!

Super happy, thanks to everyone.

https://www.youtube.com/watch?v=iWxgmYHEjR8

Now where's the rest of that todo list :)

Yeah, it's alive.