I have a 1983 1.9 waterboxer vanagon.

It is running very unstable when just started.
When it's warm theres no problem it then runs very well.

When the engine has run for around 3 minutes the problem will stop.
I've replaced all sparks and there's no waterproblem (loss of water,
overboiling or so).
Any ideas ???

Best regards
Michael
1983 1.9 wbx Vanagon