My 85 1.9 has had this problem for more than 2 years and I've never been
able to solve it. Its time to ask the experts. Whenever the van sits
overnight and its cool and damp out, it misfires until it warms up. It
idles fine, but won't rev under load without breaking up. When I say its
cool and damp, its the San Diego version, which means 50 degrees and 65%
RH. It doesn't matter if the van is in the garage or outside in the rain.
The problem is intermittent, which is one of the reasons that its been
around so long. Once the van gets fully up to temperature, the problem
vanishes and it runs fine until the next damp day, which usually is a few
weeks away. However, its finally getting worse, so its time to do
something about it.

Over the past 2 years, some of the items that I replaced were the coil,
cap, rotor, plugs, plug wires, hall sender & connector, injectors, temp
sensor, and O2 sensor. I also have cleaned all ground connections and
cable connections at the ECU, AFM, idle stabilizer, etc. I have not dealt
with the last 3 items other than simple cleaning. Next 2 simple things
I'll check are the wire & connections for the temp and the O2 sensors.

Any suggestions?

Thanks,
Walter
85 VAnagon 1.9