Aircooled VW South Africa

retrovan wrote: ↑Sat Dec 15, 2018 6:00 pm Maybe @Tony Z should come in here.....

Herman

I'm out of suggestions. It seems that everything has been tried and nothing has been found wrong, yet it continues...

When fault happens... is it mostly:

A)-Loosing power gradually over a few seconds, sometimes slight "coughing" through inlet?

B)- Instantly loosing power within a splitsecond, maybe the odd backfire through exhaust, or fast doing either on/off situation before it continually misses or eventually dies?

My 1st feeling was that the fuel line is blocked, which will only be valid if an electric fuel pump is fitted.

As when standing with ignition on would get some fuel through to run normal again till the fuel in the bowl runs out again.

This will also be valid if tank is full. Cure for this would be draining tank, flushing, and blowing backwards of fuel lines with even wire insertion to ensure fully clean.

2nd option is that hydraulic valves are fitted and when hot the valves stay open. As setting of hydraulic valves are different to standered valves.

Now these are normally not fitted to type 1 engines but could have been fitted to this one by PO.

Herman

Could it be that initially symptoms was more like A), but later became more like in B) above ?

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John Alves wrote: ↑Mon Dec 17, 2018 1:35 pm


B)- Instantly loosing power within a splitsecond, maybe the odd backfire through exhaust,

this is it,
it used to happen when cold and then would improve until motor was hot, now only happening when motor is hot.
Motor is stock standard 1500 single port

Still sounds like 90% chance of ignition intermittently cutting out.
Beetle with 1968- type ventless engine lid is known to have a good chance of common Igniter/Pertronics/Compufire issues/failure.

Reason being slightly hotter engine compartment temperature near the distributor. (Engine still gets adequate cooling airflow to heads/cylinders as air flows down straight from air intakes to fan inlet, air just doesnt swirl around distributor area.)

As a test, you could try old points distributor again. Try Retrovan's advice by slight squeezing the condenser. Or look for an old Bosch condenser.
Some advice elsewhere was to buy a condenser for a Nissan 1400 and just splice/insulate the wires as necessary to make contact.

I know the electronic ignition worked in your Ghia before, but in the weird word of fault-finding funnier things have happened.

Did it still have it's unique "vacuum only" short fat distributor? The 30PICT carb has a special dedicated vacuum connection to operate this distributor. Also using vacuum from below venturi instead of only directly above throttle valve. Distributor is fat and uses large vacuum biscuit, which provides leverage to make use of this tiny vacuum signal.
The 30PICT carb is not fully compatible with svda (mechanical + vacuum) type distributors. Engine will run, but not optimum. Economy will suffer.

Dawie wrote: ↑Mon Dec 17, 2018 2:47 pm ..................Reason being slightly hotter engine compartment temperature near the distributor. (Engine still gets adequate cooling airflow to heads/cylinders as air flows down straight from air intakes to fan inlet, air just doesnt swirl around distributor area.)
...........

Know this to be a fact as with the 4 in 1 exhaust system, as good as they are for the performance of the engine, they develop a hell of a lot of heat on the pulley tin, and the distributor get so hot it cooks the distributor parts creating expansion and electronic failure.

Expansion gets modern condensers to break down sporadically, and heat will make electronics do funny thing.

This you do not get on an water cooled or open engine.

Herman

It came with H30/31 PICT carb and a 049 points dizzy, I did install a 4 into 1 exhaust so there could be heat issues, would wrapping the silencer solve the heat issue?
it does feel like an electrical issue.
I will measure heat at dizzy with my laser thermometer on the next run.

I have also got exhaust wrap for my 4 into 1 and will only be wrapping the cross over sections that runs left to right.

Should solve a multitude of sines.

Herman

I took a few temperature measurements on tinware as shown on pic
75º at head tin
77º tinware under dizzy
101º tinware under pulley
and 275º directly on exhaust under pulley tin

I have no idea what they should be so this is just an interesting pointless exercise, maybe someone knows if these are about right or way off