Tailwind/RVGuy
Active Member
Hello All,
At the airpark where I live we had a fuel continuation issue and I would like your thoughts about what type of contamination this is and where it came from. There were four airplanes affected all of which fueled at this tank. Two of us had more issues than the others but ALL had evidence of some foreign liquid in their tank.
Here is some background followed by what happened. Long but it is important information. Access following link for pics. Zoom in on the one with the filter screen and the one that shows the little brass bowl at the bottom of the accelerator pump-- scary.
https://photos.app.goo.gl/g9J2F9MjSi9qzK3L9
• Fuel is on an airpark with two approximately 1800-gallon tanks for avgas.
• Fuel is not sold to the public.
• One compartment has been used for years with no problems. The second compartment had been empty, and we needed more capacity, so we hired a fuel tank cleaning service and had the tank cleaned.
• The supply tank fuel pump system has multiple screens and filters with the final filter being a canister filter that is designed to stop water from being dispensed.
• Back in late August 2022 I fueled at the tank. After flying to another airport my airplane quit on taxi at a low idle RPM. Started right up and I blamed it on the fact that I recently had my carb overhauled and figured I set the RPM too low. I have a wooden prop and it does not have much inertia.
• The next time I flew I drained the sump as always and got a sizable amount (half of my sample cup) of some yellowish colored liquid. This liquid had kind of an oily sheen and would leave residue on the side of the sample cup. After I drained it once that day, I did not get anymore so figured the issue was over.
• From that time on I did not fuel at that tank anymore but continued to get some of that yellowish liquid in my sample cup from time to time. Not every time but on a consistent basis.
• My friend in his RV4 also had similar problems. We then departed on a approx. week long trip where we each burned approximately 100 gallons of avgas from stops on the trip. We continued to get some yellowish liquid in our samples when sumping the tanks. It was as if it "hid out" in crevices and corners and drained to the sumps at strange times. One time in particular, We sumped our tanks in the morning with clean samples and then flew an hour or so and sumped them again and got some yellow liquid.
• Both of our engines are carbureted Lycomings
• After we got back we dug deeper and did some ethanol testing on the liquid and determined that it in fact was ethanol or some other liquid that would mix with water. We also discovered that this yellow liquid would turn to a jelly like substance that would stick to the sides and bottom of the tank. It would look like pepper sized soft particles that would eventually collect together to form large drops of jelly like substance.
• The cartridge filter on the (fuel dispensing) pump had an extreme amount of corrosion on the steel end of the filter.
• I checked my inline race car filter and found that it was almost completely plugged with a jelly like substance. See the picture in the link.
• Long story short, we determined that if we let it dry, the "jelly" would crumble and turn to dust. We both emptied our complete tank systems and dried them out using airflow from a muffin fan with a little heat to warm the air. We removed the carb inlet screens on both carbs, and they were both clean - no debris in either one. We thought we had the problem solved as we got clean sump samples and have not used fuel from the contaminated tank.
Here is what happened next-- see pics attached.
• My engine began to have a problem starting and had always started on about the 2nd blade with a simple pump of the throttle. That didn't seem to be working plus my throttle cable seemed stiff.
• I blamed the hard starting on the cold weather here in Wisconsin plus I don't have a primer
• For the stiff throttle, I disconnected the cable from the carb and discovered that it WAS NOT the cable at all but rather the carb arm moved really stiff. I determined that the accelerator pump was almost seized in it's bore. Look at the picture and zoom in on the little brass bowl with the screen in it. The screen is almost completely plugged with some gel like material completely filling the outside of the screen. Note also the white colored gel like material on the top of the check valve. This prevented any gas from being drawn into the accelerator pump plus the pump would barely move in the bore.
• Upon further disassembly of the carb I discovered more yellowish liquid in the bowl (this is 4 months or so after the contamination) and corrosion on various parts of the carb body. Also a lot of particles of jelly like material. The inlet fitting filter was still clean.
So some questions:
• The yellowish liquid is definitely ethanol or some other liquid that is an emulsifier. Where did it come from? Our fuel supplier assures us that they do not sell ANY fuel that has ANY ethanol in it.
• What concentration of ethanol would cause the corrosion?
• The tank cleaning company claims they did not use any type of emulsifier but rather just pumped out any remain liquid, inspected the walls and then scooped out any left o over debris in the tank. Does that sound like a good way to clean the tank? Is that the industry standard?
• What causes this liquid to turn to jelly when it sits in any one spot for a length of time ( in the filter or bottom of the carb)?
• This stuff (ethanol/water mixture) makes it through multiple filters in the liquid form (including a supposed water stopping filter). before turning to jelly and collecting in various parts of the fuel system. How does it do that?
• Any ideas of what else this could be and how to clean it up and get it out of the system completely? It does seem that by drying the complete system that it does fix it but my recent discovery indicates that I literally have to take the carb apart and clean it. I wrongly assumed that after I had a clean main filter and a clean carb inlet filter that my carb bowl and internals were OK it appears that was not true based on my recent discovery outlined above.
• Have any of you experienced this? if so, how did you eliminate the contamination? Did you determine the source of the contamination?
• We are confident that it is coming from the fuel dispensing tank. We cannot figure out what it is or how it got into the tank, and how it passes through all the screens and filters. Ideas anyone??
Keith
At the airpark where I live we had a fuel continuation issue and I would like your thoughts about what type of contamination this is and where it came from. There were four airplanes affected all of which fueled at this tank. Two of us had more issues than the others but ALL had evidence of some foreign liquid in their tank.
Here is some background followed by what happened. Long but it is important information. Access following link for pics. Zoom in on the one with the filter screen and the one that shows the little brass bowl at the bottom of the accelerator pump-- scary.
https://photos.app.goo.gl/g9J2F9MjSi9qzK3L9
• Fuel is on an airpark with two approximately 1800-gallon tanks for avgas.
• Fuel is not sold to the public.
• One compartment has been used for years with no problems. The second compartment had been empty, and we needed more capacity, so we hired a fuel tank cleaning service and had the tank cleaned.
• The supply tank fuel pump system has multiple screens and filters with the final filter being a canister filter that is designed to stop water from being dispensed.
• Back in late August 2022 I fueled at the tank. After flying to another airport my airplane quit on taxi at a low idle RPM. Started right up and I blamed it on the fact that I recently had my carb overhauled and figured I set the RPM too low. I have a wooden prop and it does not have much inertia.
• The next time I flew I drained the sump as always and got a sizable amount (half of my sample cup) of some yellowish colored liquid. This liquid had kind of an oily sheen and would leave residue on the side of the sample cup. After I drained it once that day, I did not get anymore so figured the issue was over.
• From that time on I did not fuel at that tank anymore but continued to get some of that yellowish liquid in my sample cup from time to time. Not every time but on a consistent basis.
• My friend in his RV4 also had similar problems. We then departed on a approx. week long trip where we each burned approximately 100 gallons of avgas from stops on the trip. We continued to get some yellowish liquid in our samples when sumping the tanks. It was as if it "hid out" in crevices and corners and drained to the sumps at strange times. One time in particular, We sumped our tanks in the morning with clean samples and then flew an hour or so and sumped them again and got some yellow liquid.
• Both of our engines are carbureted Lycomings
• After we got back we dug deeper and did some ethanol testing on the liquid and determined that it in fact was ethanol or some other liquid that would mix with water. We also discovered that this yellow liquid would turn to a jelly like substance that would stick to the sides and bottom of the tank. It would look like pepper sized soft particles that would eventually collect together to form large drops of jelly like substance.
• The cartridge filter on the (fuel dispensing) pump had an extreme amount of corrosion on the steel end of the filter.
• I checked my inline race car filter and found that it was almost completely plugged with a jelly like substance. See the picture in the link.
• Long story short, we determined that if we let it dry, the "jelly" would crumble and turn to dust. We both emptied our complete tank systems and dried them out using airflow from a muffin fan with a little heat to warm the air. We removed the carb inlet screens on both carbs, and they were both clean - no debris in either one. We thought we had the problem solved as we got clean sump samples and have not used fuel from the contaminated tank.
Here is what happened next-- see pics attached.
• My engine began to have a problem starting and had always started on about the 2nd blade with a simple pump of the throttle. That didn't seem to be working plus my throttle cable seemed stiff.
• I blamed the hard starting on the cold weather here in Wisconsin plus I don't have a primer
• For the stiff throttle, I disconnected the cable from the carb and discovered that it WAS NOT the cable at all but rather the carb arm moved really stiff. I determined that the accelerator pump was almost seized in it's bore. Look at the picture and zoom in on the little brass bowl with the screen in it. The screen is almost completely plugged with some gel like material completely filling the outside of the screen. Note also the white colored gel like material on the top of the check valve. This prevented any gas from being drawn into the accelerator pump plus the pump would barely move in the bore.
• Upon further disassembly of the carb I discovered more yellowish liquid in the bowl (this is 4 months or so after the contamination) and corrosion on various parts of the carb body. Also a lot of particles of jelly like material. The inlet fitting filter was still clean.
So some questions:
• The yellowish liquid is definitely ethanol or some other liquid that is an emulsifier. Where did it come from? Our fuel supplier assures us that they do not sell ANY fuel that has ANY ethanol in it.
• What concentration of ethanol would cause the corrosion?
• The tank cleaning company claims they did not use any type of emulsifier but rather just pumped out any remain liquid, inspected the walls and then scooped out any left o over debris in the tank. Does that sound like a good way to clean the tank? Is that the industry standard?
• What causes this liquid to turn to jelly when it sits in any one spot for a length of time ( in the filter or bottom of the carb)?
• This stuff (ethanol/water mixture) makes it through multiple filters in the liquid form (including a supposed water stopping filter). before turning to jelly and collecting in various parts of the fuel system. How does it do that?
• Any ideas of what else this could be and how to clean it up and get it out of the system completely? It does seem that by drying the complete system that it does fix it but my recent discovery indicates that I literally have to take the carb apart and clean it. I wrongly assumed that after I had a clean main filter and a clean carb inlet filter that my carb bowl and internals were OK it appears that was not true based on my recent discovery outlined above.
• Have any of you experienced this? if so, how did you eliminate the contamination? Did you determine the source of the contamination?
• We are confident that it is coming from the fuel dispensing tank. We cannot figure out what it is or how it got into the tank, and how it passes through all the screens and filters. Ideas anyone??
Keith