Fuel Tank, here's a story for ya'!

[Grizz]

For the past five years, I’ve owned a few RVs that had to fit in my man cave with 12-foot overhead doors.

The last one was a glass coach that looked perfect, but unbeknownst to me had very little maintenance for quite a while before I bought it. In fact in hindsight its pretty obvious it sat outside in Florida for a very long time with the fuel tank only about 1/3 full.

First thing I did was take it to the local truck tire shop here in Melbourne FL and had all new Michelin tires installed and full maintenance service as I was heading to Tucson the following day. The tire shop didn’t touch the fuel filters or air filter. Quality shop - not!

By the time I reached Quincy FL about 300 miles from here, the engine started missing and losing power. The fuel pressure gauge on the dash was now indicating negative pressure. I made it to the next RV park spent the night and called road service to change the fuel filters. Because of another technical problem, I returned home and by the time I got 300 miles again the fuel pressure was negative. Obviously the tank was full of crud. This problem went on for a year as every time it seemed the last of the crud was out, but the problem arose again. Hmmm maybe I was getting bad fuel. (Mind you this coach was now parked inside an air-conditioned warehouse always full of fuel.)

The following December we headed to Tucson and had no problems with fuel the entire trip. Problem solved finally? In February we were headed to Dallas and got about 200 miles from home and it started again. Must have gotten some bad fuel again even though the Murphy station was brand new. I stopped and changed the filters, but they were clean. We turned around and got home with a few hick-ups. The problem now: the engine would cut off like it was completely out of fuel, but would restart by the time the speed dropped 20 mph or so.

Enough fooling around with the fuel tank and lines! I took the coach to an independent well know service garage in Sanford to have a new tank made and installed. When I got there he said he could drop the original and clean it and the lines for $1500 (the cost of a new tank). The tank is stainless steel. The bill he handed me for that was $3600, but that’s another story.

It turns out that the tank was full of biological growth from being parked so long mostly empty. When I parked it inside after the Tucson trip, I added Biocide as a precaution to a full tank of fuel. The Biocide killed everything in the tank and it was floating around like jellyfish in the fuel. When a glob of it got into the fuel line it went through the filters, but of course would not burn in the engine, so it was like turning the ignition off until it flushed through.

What’s the moral to this sad tale? Don’t ever park (store) your coach with a partly empty fuel tank. If you feel Biocide is needed, put it in a full tank of fuel and let it set a couple of weeks. Then get the fuel polished before you crank the engine. Had I done that it would have saved me $3600 and an awful lot of aggravation?

Thinking back, I should have had the tank pulled and cleaned after the 2nd set of filters were needed. Duh!

[Texas 40]

Another great insight. Thanks Grizz.

[Gil_J]

Your story is one often told and feared by yachtsmen. The best way to prevent this is to use our coaches.

[JIM KELLER]

Not sure what " Polished Fuel " means.

[Gil_J]

Not sure what " Polished Fuel " means.

Fuel polishing is nothing more than running your fuel through a high speed pump and filters. There are 2 lines ran into your tank. One sucks the fuel out and delivers it to the filters and the other returns the fuel with force to agitate the remaining fuel. Typically, there will also be a fuel bladder if you have too much fuel in your tank. If you are near marinas with diesel powered boats you will find mobile fuel polishing services.

[Joe Camper]

Jim I can't cut and paste on my phone but if u go to prevost specific topics then click drivetrain and about half way down the first page I had a thread on a fuel polishing module I put on a Royal.

Someone please cut and paste that thread here please.

This Royal had a second water and fuel seporator filter for the aquahot that we used to plumb it to so the engine filter was never effected should anything bad get filtered out. It was easier to change and a bit smaller than the engine filter and less money too.

[Gil_J]

Here's the thread Joe was writing about: http://forum.prevostownersgroup.com/showthread.php?7096-Fuel-Polishing-Module

Although the Parker unit Joe references will work. It won't be as effective as a high speed pump and dedicated filter. I would not be a big fan of of using the engine's primary filter.

Here's an example of one that I used on my boat. This is more capacity than needed in the coach as I had a capacity for 700+ gallons of fuel. This will give you a good diagram of the preferred method of plumbing and valving a fuel polishing system.

http://www.gulfcoastfilters.com/fuel_polishing.htm

http://www.gulfcoastfilters.com/images/FPS_240B.jpg

Personally, I wouldn't think we need a fixed system. As I've said before, just get out and run the bus. In the rare case you have fuel problems, have your fuel polished or simply drained.

[JIM KELLER]

Here's the thread Joe was writing about: http://forum.prevostownersgroup.com/showthread.php?7096-Fuel-Polishing-Module

Although the Parker unit Joe references will work. It won't be as effective as a high speed pump and dedicated filter. I would not be a big fan of of using the engine's primary filter.

Here's an example of one that I used on my boat. This is more capacity than needed in the coach as I had a capacity for 700+ gallons of fuel. This will give you a good diagram of the preferred method of plumbing and valving a fuel polishing system.

http://www.gulfcoastfilters.com/fuel_polishing.htm

http://www.gulfcoastfilters.com/images/FPS_240B.jpg

Personally, I wouldn't think we need a fixed system. As I've said before, just get out and run the bus. In the rare case you have fuel problems, have your fuel polished or simply drained.

Actually my interest is for the on site stand by generator with the fuel tank below it that runs the compound. What do you think ?

[Gil_J]

Jim,

Those large standby generators typically have under generator fuel tanks that are uninsulated and made from steel. Unless, these standby generators are frequently exercised they would likely be prone to bad stuff growing in the tank. This would be worse in areas of high humidity.

Run it at least monthly and frequently check the fuel filter(s). If you can't run it or the filters become restrictive too frequently, a fuel polishing system may be beneficial. The only downside is the cost of the polisher.

FWIW, I have never seen a fuel polisher on a telecom shelter's standby generator. These generators are run monthly for at least 8 hours.