Re: hard starting-fuel
Reply #4 –
John,
Have been through lots of times with customer's cars and at sea. You may have picked some up in Mexico where the conditions are ideal for growth. Lots of humidity with resulting condensation in either the station tank, your tank or both. Parked next to the ocean in Sayulita with a partial tank may have been the source of the water with the algae arriving at a later time.
Algae grows nicely in the interface between the fuel and the water in your tank. In the old days, we would buy a quart of the algae killer and after one treatment and a couple of filter changes, that would be it. We were warned not to dump any of the fungicide down the sink as one quart was enough to put the sewer plant out of business. Now days, the stuff is watered (bad choice of words?) down a bit but will still do the trick with regular use. After you add the biocide and change filters, you might use the fuel in the tank until it gets toward the bottom, raise the driver's side a little and then look down in the tank with a mirror and led light. You will be able to see any water and algae as they will collect at the low point, in this case, right below the filler cap. My U300 tank holds 150 gallons and each inch of fuel up from the bottom equals exactly 6.0 gallons with the rig level. You can then use a hand pump to remove any water you see at the bottom. Look for any algae at the same time. Algae also like fuel gauge senders but it sounds like you caught it early so probably not a problem.
When changing filters, I like to fill the filters almost to the top and then install leaving them a couple of turns from seating the gaskets. I then pump fuel with my hand pump (or electric if you have one) until the fuel runs out each filter and then tighten them so no air gets trapped. Your Cummins may be quite sensitive to any air in the system when you try to restart after the change.
After killing the algae, the dead stuff will still clog filters so make sure to carry several spares with you. Since a diesel uses only a small portion of the fuel it pumps from the tank with the rest returning to the tank via the return line, it will filter all the fuel in the tank in fairly short time. The less fuel in the tank, the quicker the fuel will be completely filtered.
Continue to use the fungicide and you should be in good shape.
Pierce
Topic: hard starting-fuel