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Topic: Genset white exhaust (Read 965 times) previous topic - next topic

Genset white exhaust

Quote from: ncaabbfan –
I have not tried to start the genset yet as I want to replace the 1-2 feet of hose where it makes the bend to go into the genset fuel pump.  The existing hose is cracked fairly badly and last winter I was getting white exhaust when I tried to start the genset. So I presume I am getting air in the hose due to leaks in these cracks.  So I do not know how the batteries will spin the genset diesel now.

Somebody will correct me if I'm wrong, but I think white smoke indicates it's getting fuel, not that it's getting air.
1996 U270
Build #4846

Re: Genset white exhaust

Reply #1 –
White smoke is unburnt fuel, could be from no glow plug action.

Re: Genset white exhaust

Reply #2 –
In very cold weather, I believe that white smoke on start up is normal.  But it should clear up very soon.
1994 U225
build #4514

Re: Genset white exhaust

Reply #3 –
Quote from: Dave M –
White smoke is unburnt fuel, could be from no glow plug action. 

Where is the glow plug located on the Isuzu engine?  How can I check it to determine if it is operating properly?

Thank you.
Morris and Janice
1997 U270 36'

Re: Genset white exhaust

Reply #4 –
Morris & Jannis,

White smoke at startup may be OK for a few seconds in cold weather. There are 4 glow plugs (if you have the 4 cylinder engine). They are located right below the intake manifold. Using a 12V test light, connect the clip to ground and push the sharp end onto the nut at the end of any of the glow plugs. It should light when you preheat the plugs. If no light, check relay "G". To check each plug separately, unscrew the nut at the end of each plug and remove the wires. Connect the clip to 12V positive and go to each plug with the probe. The light should come on if they are good. No light indicates an open circuit (they are bad). If one is bad, it will cause hard starting or in cold weather, it may not start at all. I have attached the wiring diagram for my U300 but should be close for yours. I don't have any idea where the relays are located on your model. Check to make sure the electric fuel pump is working. An auto electric shop should be able to diagnose the problem with the attached schematic. I have the Power Tech Manual if you should need it.

Best,

Pierce & Gaylie
93' U300/36
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)
 

Re: Genset white exhaust

Reply #5 –
I wanted to give the most current status update on this issue.  This morning, I tried starting the genset again. As previously, it just cranked and cranked, but no attempt to start at all.  Got the white exhaust again this morning.  So I decided, what the heck, I will go ahead and replace a short section (around 6 inches or so) of the fuel hose where it bends to connect to the engine. This short section had quite a few small cracks in the surface of the hose around the bend.

I replaced the short section and tightened the hose clamps down tight on the hose barb connector.  I tried to start the engine again. Again, it cranked and cranked....the almost immediately started running.  So I ran the engine for around 1 hour and 40 minutes.  I had disconnected the shore power cable so all coach AC power was from the genset.  I turned on some overhead lights and the heat tape in the air conditioning unit.  All checked out fine.  After the heat tape had raised the coach temperature, I turned on the air conditioning unit.  It checked out fine.  This was while the genset was running and providing power to the coach.

After the air conditioner started cooling down the coach, I shut it off and killed the genset.  I immediately cranked the genset again and it immediately started. 

So I hope the problem was slight air leaks in the fuel hose at the bend.  I will know more when I try starting the genset again in a few days.

I greatly appreciate everyones assistance.  Thank you very much.

Morris and Janice
1997 U270 36'