XC90 Fuel Tank Sabotaged need removal or cleaning advice Topic is solved

[cn90]

- I have attached a random photo taken from ebay to show the typical shape of the XC90 fuel tank.
You can see 2 openings...

- I think water is a good solution for cleaning.

- To drain water:

a. Buy or rent or borrow a 120V "Utility Pump". This is the type of pump people use to pump minor flood in the basement etc.:
https://www.amazon.com/Portable-Transfe ... 01N9MVXFA/

b. Get a clear hose and siphon it out as the tank sits high and you can use the principle of siphoning by gravity.

- To dry the tank: once most of the water is out, if you have a leaf blower, then blow into one opening while allowing air to escape the other opening.

- To make sure it is nice and dry...use an old T-shirt or Bath Towel and drop it inside...Then remove it.

- Then add fuel with Ethanol (as others said, Ethanol mixes well with water). The Ethanol will remove remaining water droplets/moisture.

- I'd replace the Fuel Filter twice: once after the cleaning. And maybe 500-1000 miles later.
But make sure when you disconnect the fuel hose that nothing (no debris) is UPSTREAM of the fuel filter.

- Dose anyone know the trick to "back flow" the feed line from the fuel filter to the engine? This way, any debris that is in that line can be pushed backward to the outside world.

XC90-Fuel-Tank.jpg (261.23 KiB) Viewed 1810 times

[mrbrian200]

- Dose anyone know the trick to "back flow" the feed line from the fuel filter to the engine? This way, any debris that is in that line can be pushed backward to the outside world.

With the fuel pump and fuel filter both disconnected easy. I might go so far as to disconnect the fuel line at the injector rail and flush the line all the way back from there just to be extra cautious.

As far as sucking out the water, I would use a wet/dry shop vac with the smaller 1-1/2 in flexible hose. After drawing standing water you could just leave the hose inside and let it run for awhile to dry it out better. I've scrubbed the inside of a filthy tank or two with carpet/upholstery solution or pine sol + ammonia with a rag on a short stick. So long as you rinse thoroughly with clear water and dry it out the cleansers don't hurt a thing.

[Jeeptroll]

THE IN-SITU TANK CLEANING PROCESS
All right. I finally had time to address the sabotaged fuel tank.
When I removed the pump the second time it was full of crystals and plant debris again. The fuel pump basket was choked full of the plant material . As the tank siphon pump was filling the basket, the basket was retaining much of the debris to the extent that the pump inlet screen on the bottom of the basket was clogged. The engine seemed to get enough fuel at idle but not to accelerate quickly. P0089....it all makes sense now.
I jacked up the car an tilted it toward the rear to make sure the last of the fuel would be accessible from the hatch. I disconnected the battery, removed the seats opened the hatches and removed the fuel pump.
I purchased a old style 12v in line fuel pump for a "carbureted " engine. I had an old computer power supply that I rigged up to supply 12 volts. To keep things safe I had a fan in front of the car circulating the air and fumes out of the garage. When I hooked up the fuel pump I made sure it was well grounded. The power supply was located about 10 feet from the car when I turned it on. I used a hose on the inlet to pump-out the last few gallons of fuel. This pump actually clogged a few times but surprisingly I was able to remove almost all of the fuel. To get the last few ounces, I used a sponge.

I left the hatches off and allowed the vapors in the tank to dissipate overnight.
By the next day the fuel was removed and the vapors are gone. It is safe to begin cleaning. I taped a rag on a plastic rod and wiped the inside of the tank to explore the corners. In the corners remained a good bit of plant material and the crystals had become sticky and gooey. By now I am sure the crystals are sugar.

In this next step, I filled the tank with a universal solvent, water, which dissolved the sugar and floated the plant material. Using a shop vac I removed the floating debris and water. I also flushed the filler neck. I repeated this process three times on each side of the tank. I put a fan over the hatch and dried the tank for six hours with air. Make sure you blow air down the filler neck for it retains a good bit of water/ fuel.
I rinsed the fuel pump basket inverted with a garden hose and let it dry.
Tonight I reinstalled the pump and filled up with 5 gallons of fuel from the gas can.
The XC90 V8 started right up and ran smooth. My initial highway test was great with no hesitation on acceleration. I wlll leave the back seat out for a few days and recheck the fuel pump basket and maybe change the fuel filter.
The cleaning process was relatively quick and easy compared to removing the fuel tank. It seems like a success at this time. Safety first!!!! I didn't burn anything down!!!

I want to thank the good folks on this forum for all the excellent advice.
After this unknown person stole my gas and sabotaged my tank with sugar and debris, I was starting to loose faith in humanity. On this forum it was good having some help getting it fixed! Faith restored!

[cn90]

Make sure you fix the fuel door lock to be sure it is secure.
Glad you fixed it w/o removing the fuel tank.
Yes, change the fuel filter ASAP!

I wrote fuel filter DIY a few years back:

viewtopic.php?t=64409

[mrbrian200]

Probably the last thing you will want to do before reassembling the back interior is connect an OBD tool (either VIDA or a tool that displays live data), Have a passenger watch the fuel pressure as reported through CAN data as you do a hard acceleration/WOT up to highway speed. It should stay firm around ~59 psi +/- 2 or 3 psi. If you still have a flow restriction somewhere you'll see a pressure drop during WOT which will recover as you ease your foot off the gas.
If you have access to VIDA you can use the graph function, set it to display fuel pressure, accelerator position, and speed. Press "start" before you take off. Press "stop" after you bring the vehicle to a safe stop, then zoom in and review whether the fuel pressure held steady or not during the run.