Hard to start when warm

[A Capps]

I have been through this before. I cant remember what causes this - the bus fires right up in the morning without much cranking at all (remeber this fact). However, when I am driving around and the car is up to normal temperature, I come out and have to crank and crank for like 15 or 20 seconds before it finally starts. It is always like this, once it is up to tenperature.

The accelerator pump is working.

Too lean?

Too lean doesnt make since since I am pumping the accelerator pump

If the fuel bowl is leaking down, then why does this happen instantly, when there hasnt been enough time for the fuel bowl to leak down?

Any ideas?

If I recall, there is a known cause and correction but it has been 36 years since I knew these things.

A Capps

[Scott Novak]

There are a couple of reasons. The fuel mixture could be too rich. When cold, the fuel mixture does not vaporize as easily and running a richer fuel mixture will help start the engine just like a choke does by also richening the fuel mixture.

You could be running over-rich because your choke is not adjusted correctly, or the electric coke element may be defective, or the wire to the electric choke element may not be connected, or the connector could be loose, or the connector on the wire could be poorly crimped not making good connection.

You could simply have a carburetor that is jetted overly rich.

A leaky float valve doesn't require much engine off time to force extra fuel into the manifold and flood the engine.

The typical OEM VW Bosch ignition coil and the Bosch Blue coil, with the internal ballast resistance, decrease output voltage and current as they heat up. The lower output voltage and lower spark current current also makes it more difficult to start. You might actually have a defective ignition coil.

An over-rich fuel mixture may be fouling your spark plugs to some degree making it more difficult to start.

I'd first check to see that the choke is fully open when your engine is warm, as that is the most likely and easiest to check.

Scott Novak