Question : I
HAVE a 1968 1.6-litre Volkswagen.
If I travel long distance and stop for rest, the car will not start until
the engine is cooled for 45 minutes.
I have changed to a re-conditioned electronic distributor and four
platinum plugs as well as the ignition coil.
The problem still remains.
You will have noticed that the flat 4 Volkswagen engine has the carburetor
sitting on top of the engine and there is a heat shield normally fitted
between the carburetor and the intake manifold.
Even with this heat shield in our tropical climate, the engine
compartment gets quite hot.
When you stop the car, the heat build-up is quite high and this causes
the fuel in the carburetor to literally boil ( evaporate ) and you will even
get vapour lock in the fuel lines.
As a result, there may be too little fuel in the carburetor to start and
with a vapour lock it will take some time to pump the fuel into the
carburetor to the right level to start.
My suggestion is to fabricate a larger heat shield for the carburetor and
re-route the fuel line away from the hot parts of the engine.
You could also try changing the fuel pump to an electric ( SU-type ) one,
as the pump will prime the carburetor immediately you turn on the ignition.