Exhaust pipe:
The stock DA-BA-6 heater exhaust pipe is a short elbow that exhausts under
the vehicle on the Vanagon version. The gas 75-79 Bus heater often has three
or more feet of exhaust pipe.

If it smokes excessively, there can be several reasons for this, besides the
fact that Diesel doesn't burn as clean as gas. Low voltage, or dirty points.
Fuel pumps out of adjustment.

With the Diesel, the system is controlled by an ECU behind the glove box that
controls the startup cycle-this can be defective as well.

The ECU delays operation of the system until the glow plug is heated up,
unlike the instant operation with the gas model.

If the glow plug is worn out, it will burn poorly at startup. There is also
a coil in the system, and the spark plug electrode could be worn, or need
re-gapping.

Critical for the diesel is a good glow plug, which is fairly easy to check
with a 22 mm wrench,
unrestricted combustion blower intake hose-long black plastic hose running
along the drivers side of the heater,

and good grounds/voltage, which should be engine operation voltages above
13.5 volts for best operation.

The heater also has an inline water separator and fuel filter that should be
checked.
Inspect the fuel lines and replace if they are cracked or leaking before
further testing.

And, if the van has been undercoated, make sure there isn't any tar on the
heater which could heat up and ignite.

These heaters are designed to run no more than two timing switch cycles.

They were intended to heat while driving, not for extended stationary use.
Because of the location of the tail pipe in all models, you have to be
careful not to park over flammable materials like grass or leaves.
The Bentley has a section on this heater on page 82.14a all water cooled.
The first page shows the new style glow plug. If yours has the new style,
check to see that the high tension cable from the coil to the spark plug has
been removed, and that terminal 15 is disconnected, as per instructions on
the first page.

Robert Keezer
1982 Westfalia