Webasto Fun & Games - Here we go again

[Denis R]

Well, a couple of months back I decoked the Webasto following Chris's guide - thanks for that, it's really helpful! Flippin' amazing the thing was still running! Anyway, yesterday it was running fine and this morning it won't fire up.

It goes through the 'purge' phase ok, fan winds down as usual. Normally I then get a slight dimming of the lights (I guess as the glow plug comes on) then the fuel pump kicks-off and we're away.

This morning it goes immediately from the purge then slow down phase straight to a 'post non-start purge and shutdown'.

Questions:

Does the unit know if the glow plug has burnt out and is open circuit, and therefore goes 'directly to jail'?

If the plug is still heating and the pump's failed, will it still give the impression it's going through the light-up phase or again, does it go straight to shutdown?

I suspect the glow plug, as when I stripped the burner for the decoke, the plug looked very heat affected on the outside of the burner and the white ceramic looking insulator was cracked. The plug wouldn't extract from the burner tube it was so glued in, so I left it where it was...

Before I go off and buy a new burner assembly, ideas anybody?

[jenlyn]

Well, a couple of months back I decoked the Webasto following Chris's guide - thanks for that, it's really helpful! Flippin' amazing the thing was still running! Anyway, yesterday it was running fine and this morning it won't fire up.

It goes through the 'purge' phase ok, fan winds down as usual. Normally I then get a slight dimming of the lights (I guess as the glow plug comes on) then the fuel pump kicks-off and we're away.

This morning it goes immediately from the purge then slow down phase straight to a 'post non-start purge and shutdown'.

Questions:

Does the unit know if the glow plug has burnt out and is open circuit, and therefore goes 'directly to jail'?

If the plug is still heating and the pump's failed, will it still give the impression it's going through the light-up phase or again, does it go straight to shutdown?

I suspect the glow plug, as when I stripped the burner for the decoke, the plug looked very heat affected on the outside of the burner and the white ceramic looking insulator was cracked. The plug wouldn't extract from the burner tube it was so glued in, so I left it where it was...

Before I go off and buy a new burner assembly, ideas anybody?

 

regular bottles of redex diesel and water dispeller in your tank will help, also, make sure your radiators are correctly balanced

[steelaway]

Well, a couple of months back I decoked the Webasto following Chris's guide - thanks for that, it's really helpful! Flippin' amazing the thing was still running! Anyway, yesterday it was running fine and this morning it won't fire up.

It goes through the 'purge' phase ok, fan winds down as usual. Normally I then get a slight dimming of the lights (I guess as the glow plug comes on) then the fuel pump kicks-off and we're away.

This morning it goes immediately from the purge then slow down phase straight to a 'post non-start purge and shutdown'.

Questions:

Does the unit know if the glow plug has burnt out and is open circuit, and therefore goes 'directly to jail'?

If the plug is still heating and the pump's failed, will it still give the impression it's going through the light-up phase or again, does it go straight to shutdown?

I suspect the glow plug, as when I stripped the burner for the decoke, the plug looked very heat affected on the outside of the burner and the white ceramic looking insulator was cracked. The plug wouldn't extract from the burner tube it was so glued in, so I left it where it was...

Before I go off and buy a new burner assembly, ideas anybody?

 

 

 

Hi

 

I hope this helps.

If you send me your Email I'll send you the complete manual

 

Alex

 

3.1.1 Switch On/Starting

Fuel

When starting the vehicle engine the heater goes in

standby. With a water circuit temperature below 60 °C and

an outside temperature below 5 °C (option with outside

temperature sensor) the starting sequence commences.

The glow plug and the combustion air fan are activated.

After 30 seconds the fuel dosing pump starts operation

and combustion air fan operation is suspended for

3 seconds. Subsequently the combustion air fan speed is

increased in a ramp within 57 seconds to nearly full load

operation.

After reaching full load fuel delivery within this period the

glow plug is deactivated and the combustion air fan

operation increased to full load.

During the subsequent 45 seconds as well as in normal

operation the glow plug functions as flame sensor to

monitor the flame condition.

After all these events the automatically controlled heating

operation starts. In case of a no flame condition or a

flameout, a restart is automatically initiated. If the no flame

condition persists, fuel delivery is stopped and the heaters

enters an error lockout with a run-down of the combustion

air fan.

Diesel

When starting the vehicle engine the heater goes in

standby. With a water circuit temperature below 60 °C and

an outside temperature below 5 °C (option with outside

temperature sensor) the starting sequence commences.

The glow plug and the combustion air fan are activated.

After 30 seconds the fuel dosing pump starts operation

and combustion air fan operation is suspended for

3 seconds. Subsequently the combustion air fan speed is

increased in two ramps within 56 seconds to nearly full

load operation. After a stabilisation phase (constant

speed) of 15 seconds the combustion air fan speed is

again increased in a ramp within 50 seconds to nearly full

load.

After reaching full load fuel delivery the glow plug is

deactivated and the combustion air fan operation

increased to full load.

During the subsequent 45 seconds as well as in normal

operation the glow plug functions as flame sensor to

monitor the flame condition.

After all these events the automatically controlled heating

operation starts. In case of a no flame condition or a

flameout, a restart is automatically initiated. If the no flame

condition persists, fuel delivery is stopped and the heater

enters an error lockout with a run-down of the combustion

air fan.

A flameout during normal combustion operation causes

an automatic restart.

3.1.2 Heating Operation

Fuel

When the temperature rises to reach 72 °C the heater

switches to the energy saving part load operation. A rise

in temperature up to 76.5 °C causes the heater to enter a

control idle period. This also happens when exceeding a

total heating operating time of 76 minutes.

After cool-down of the coolant to 71 °C the heater

resumes part load operation. Another rise in temperature

to 76.5 °C causes the heater to enter again the control idle

period. A drop in the coolant temperature during part load

operation due to an increased demand in heat will cause

the heater to switch to full load operation at 56 °C.

Diesel

Heating operation for the Diesel type heater is identical in

the sequence of events. Should the coolant temperature

drop during the control idle period to but not below 71 °C

within 900 seconds, a subsequent drop in the coolant

temperature below 71 °C causes the heater to perform a

regular starting sequence into full load operation.

A drop in the coolant temperature during part load

operation due to an increased demand in heat will cause

the heater to switch to full load operation at 65 °C.

3.1.3 Switch Off/Deactivation

When turning the engine off the heater is deactivated.

Combustion stops and run-down commences. The

combustion air fan first continues operation to cool the

heater down (run-down) to be automatically switched off

afterwards.

NOTE

The run-down time and the combustion air fan speed

depend on the heater operating condition at the time of

deactivation.

Run-down time is for:

Fuel

168 seconds when deactivated in full load operation and

157 seconds when deactivated in part load operation.

Diesel

175 seconds when deactivated in full load operation and

100 seconds when deactivated in part load operation.

Dependent on the software variant implemented in the

control unit

Edited February 9, 2010 by steelaway

[Denis R]

Useful, thanks. Well after the 30 second purge the fan momentarily stops, but not for 3 seconds. The fuel pump doesn't start either. The fan stops for about a second then goes to a 'full blast' purge then shuts down. There is no re-start attempt. It shuts down completely but the flame indicator stays lit on the Webasto timer.

[jenlyn]

Useful, thanks. Well after the 30 second purge the fan momentarily stops, but not for 3 seconds. The fuel pump doesn't start either. The fan stops for about a second then goes to a 'full blast' purge then shuts down. There is no re-start attempt. It shuts down completely but the flame indicator stays lit on the Webasto timer.

i had the same problem, was a matter of balancing the radiators, then adding redex and water repellent to my diesel tank, i have done this with several webastos, and thus far has cured the problem

[steelaway]

Hi

 

Have you tried starting it with the engine running??

 

Alexl

[Albin Vega]

Sounds like a low voltage shut out.

 

Pull the fuses on the unit and wait 5 mins, Make sure your batteries are well charged and put the fuses back and try again.

[nb Innisfree]

Don't know if it's the same as a 12v Mikuni which has low voltage start up mode, this bypasses resistor which is in parallel with glowplug so giving it higher voltage, a bit like the ballast resistor on some cars in the 70s which had 9v coils.

[magnetman]

Not very helpful but I had an eberspacher diesel fired heater for a while and at times it did seem like a nice system.

 

after a while I began to discover that these systems generally have 'issues around reliablilty' and in the end it became necessary to investigate some sort of repairs. I understand that it is possible to adjust the settings by connecting the heater to a computer and having done some research on the internet I discovered the ideal reprogramming device.

 

fortunately I already had one in my tool kit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited February 9, 2010 by magnetman

[Denis R]

Thanks for the replies everyone. Just to 'close the loop' on this, I got a message from Chris which answers the original question "Does the unit know if the glow plug has burnt out and is open circuit, and therefore goes 'directly to jail'?" The answer is 'yes'.

All the symptoms I have point to the glow plug, so it's burner out time...