Diesel Heater Problem

[dawnsall]

I have a Volvo Flygmotor AB 041-D, similar to an eberspacher. The problem seems to be that there is too much fuel being pumped into the combustion chamber, ie it starts OK, then I get black smoke out of the exhaust, it overheats and it stops. Has anybody got any ideas or do I need to bin it? Thanks in advance for any input.

 

[chriscallender]

At least on an Eberspacher, each pulse of the pump delivers a calibrated amount of fuel into the heater, and there is a procedure given in the Eberspacher technical manual to check that the correct amount of fuel is being delivered (something like run the heater for 90s with the fuel pickup from a measuring cylinder and the number of cc of diesel used should be within some range).

So if too much fuel is being delivered, a new pump would fix it, or possibly the pump can be adjusted but for an Eberspacher I think that would be a dealer job.

However, from experience (don't ask...) I'd say that fuel metering problems are more likely to result in the heater being difficult to start rather than the symptoms you describe. Again, for an Eber, black smoke would be a sign that the gauze around the glowplug was needing replaced or it was needing decoked (that could maybe cause overheat too). My guess is that if it was "just" too much fuel it would even run cooler (if at all) since there is incomplete combusion and unburnt fuel in the exhaust.

All based on Eberwhatsit experience so take it with a pinch of salt, unless this Volvo heater is really just an Eber with a Volvo badge on it.

Chris

 

[Leighb]

I have the Ardic 042-D - also made by Volvo Aero Corporation - which is I guess the successor to yours.

In the service book it suggests the following causes for the heater starting but soon cutting out ( does not mention black smoke though)
Flame sensor dirty sensor glass needs cleaning
Break in flame sensor circuit ? electrical fault, may need new sensor.

If heater is forming soot - ? also black smoke

1. Restricted air supply, check if air intake or exhaust outlet are blocked.
2. check the fan is running normally
If soot formation has been going on for some time, clean the heat exchanger internally.

Too much fuel supplied, check the fuel restriction has not been removed, or has wrong hole size.

Not sure if this helps at all?

If the heater has not been stripped down and cleaned recently then that might a useful first step.

 

[bobgarrett]

I have the Ardic 042-D and last year it would work for a few minutes then cut out. I suspected a shortage of air supply but proved that wasn't the problem. I also tried cleaning the flame sensor to no avail. Eventually I found that if operated on half power it did not cut out.
Since it has not been serviced for at least two years - through hardly used my next move will be to clean it myself or get is serviced and cleaned.
Anyone know who services these now or where I can get a service manual?

 

[Leighb]

Where are you based? No data in your profile.
If on the east coast there is a local marine gas and heater engineer who is familiar with them. He looked at mine, when he was looking at some gas work I wanted done, and basically said "If it is working leave well alone"

I do have manuals for it and might be able to photocopy them if that would help.