Rough Running, Crude in Racor

[johnbrowder]

When I started the bus after sitting about 3 weeks, it fired immediately, but died quickly after a few seconds. It took several seconds of cranking to restart, but then seemed to run fine. on a 300 mile round trip, I experienced a few episodes of:
1. Loss of power
2. Stumbling vibration
3. Boost drop off

Each time, I would back off power, and reapply, boost would come up and power seemed normal. No DDEC codes thrown.

I assumed it was the fuel filters. It has been right at 1 year and 7500 miles since they were changed.

So today I changed the primary (Racor) and secondary (spin-on) filters. The exterior of the razor was BLACK. There were also black particulates in the Racor bowl. I disassembled and cleaned out the bowl, and unscrewed the vortex from the filter housing.

Inside the bore of the vortex was abundant black material, looking like shredded rubber. I cleaned all that out with WD40, forceps, and compressed air. There was nothing slimy about the material, and there was no water visible in the bowl I reassembled everything and all appears well.

Road test in a week or so.

Photos attached.

This has raised several questions in my mind:
1. Is this normal from normal operations?
2. What is the black stuff, is it part of my fuel line?
3. Is filter media normally black on service (I have never seen this in marine applications)
4. Is it normal for the vortex to clog up?
5. Does anyone install the Racor Vac Gauge in place of the T-handle? I have always done this on boats to monitor excess suction indicating clogged filter or collapsed line.

Any thoughts?
Filter:
Filter.jpg

From Vortex:
From Vortex.jpg

From Bowl:
From Bowl.jpg

[Pete]

John, looks like algae to me. How old is the fuel? What climate has the coach been in? Was your fuel tank kept topped off?
I have not as yet experienced algae in the fuel, but have seen situations that looked like this.

[dreamchasers]

John,

Looks like a mess! Mine was not as bad as what you have shown.

I had once experienced algae or water in diesel. It looked very similar to what you have shown. When I first saw it, you can only image what when through my mind for possible solutions. I captured a small sample and had it analyzed. Sure enough, it was water or algae. I have since learned that diesel can attract small amounts of moisture and the moisture can turn into algae. This algae can form in a storage tank that does not have proper agitation and filtering. I thought the algae issue I had was a result of diesel storage tanks (Flying J) being depleted (during hurricane Katrina in Mississippi).

After I replaced my filters a couple of times while running the contaminated diesel through the engine, all cleared up. It was frustrating, but it did clear up.

Good Luck,

Hector

[johnbrowder]

John, looks like algae to me. How old is the fuel? What climate has the coach been in? Was your fuel tank kept topped off?
I have not as yet experienced algae in the fuel, but have seen situations that looked like this.

Last fuel was purchased in mid October at Pilot in Meridian, MS. Was at the end of 6 weeks out west with fuel purchases at some low volume locations.
Bus is stored in 60 degree heated indoor space in Knoxville, TN
Tank was recently stored 1/2 full.

[Pete]

When storing the coach in cool weather, try and keep the tank full so that no condensation or minimal condensation can occur as the atmosphere gets cooler than the fuel allowing condensate to build up.
My bet is that is what has happened. I know during my days of flying that is what we were taught. It is most important in cool/cold weather. Don't know how much fuel you still have from that fill up, but the remaining fuel can be "polished" to remove the balance of the algae, or burn it, and keep changing filters. Then keep the tank FULL in cold weather. (Just my .02 cents worth)
Good luck!

[Ledo]

I had the exact problem with an earlier coach and it was an algae problem. I now add an additive to my fuel ever so often which is highly concentrated algaecide for fuel of which an ounce or two treats 2000 gallons. Ill add it every 4th or 5th tank just to keep a mixture going.

[BoaterAl]

I'am going along with the above as algae due to water contamination. As your bus is still running I would do a 100 mile trip and change all filters again. As your photos show algae caught in your filters they have done there best to catch the crud until they can do no more. Fuel starvation is then the next level.
Racor vac gauges are not recommended in most highway applications due to the fact to being exposed to flying objects. In the marine applications the enclosed engine rooms offer protection for the gauge and secure from vibration being mounted on a bulk head.
The algae additive is a must in your case and the directions will suggest a double dose first time around. It's expensive ($20.00 plus) but cheaper then a fuel polishing treatment for sure.

[Jon Wehrenberg]

Ditto all the above. If you research algae you will find it is not uncommon, especially when the temps get warm and the atmosphere is humid with a partially full tank breathing in and out as temps change slightly up and down.

There are some debates about treatments with some advocating the use of treatments, and others being concerned about treatments sloughing off accumulated algae and making the problem worse. I suspect a little internet search can find more points of view to confuse an already confusing issue. The best solution is to keep a close eye on the Racor and change filters as often as required until the algae is no longer an issue, with the ultimate solution to be to run a lot of fuel through the tank as possible. Frequent operation of the coach is a guaranteed method of never experiencing algae. This issue is not related to buses or trucks exclusively, but can impact any device with diesel fuel including airplanes which use Jet A. It is very common for aircraft operators to routinely add Prist to fuel as the plane is being refueled as a precautionary measure, but I do not know if it is advisable for our buses.

I hate having long periods between uses of the coach for the very reason you are experiencing. Thank goodness the Racor bowl lets you see some of the accumulated crud and enables you to react quickly.

[BoaterAl]

Here is another product that will remove water from diesel fuel. Going by several brand names is ISOPROPYL ALCOHOL which is a premium water absorber. Most NAPA stores carry it.

Be sure to read the label for 100 % ISOPROPYL and not the regular run of the mill menthol alcohol.

[LNDYCHT]

I see algae quite frequently in my business ( Marine Repairs) and that is what it looks like to me. As others have suggested it did not necessarily grow in you tank but was likely pumped in.
I recommend algacide and conditioner to all my clients and the ones that use it have very few problems. I personally will not put fuel in any of my equipment without supplementing it with Racor conditioner and algacide.

http://www.parker.com/portal/site/PA...word=ADDITIVES