Strange problem with bubbles in the fuel

Get it all out.

Filters, Too. Get them gone. Fresh new filters.

Gasoline is a very very very explosively STUPID thing to do to a 18 wheeler. You can now need a 70,000 dollar engine and everything with it because bonehead put gas into a fuel tank.

Hell the flash point of gasoline liquid is so low that just heating the fuel is enough to light it. Once it lights the gasoline, the desiel will go up like a bomb.

 

I think you have flash point confused with autoignition.

"The flash point of a volatilematerial is the lowest temperatureat which vapors of the material will ignite, given an ignition source.

The flash point is not to be confused with the autoignition temperature (the temperature at which the vapor ignites without an ignition source) or with the fire point (the lowest temperature at which the vapor will keep burning after having been ignited and the ignition source has been removed). The autoignition is higher than the flash point, because at the flash point the vapor may cease to burn when the ignition source is removed.

Neither the flash point nor the fire point is dependent on the temperature of the ignition source, which is much higher."

https://en.m.wikipedia.org/wiki/Flash_point

 

"Here's a couple of scenarios we've come across. Someone calls us at the Bell office and starts to describe a situation where they had a diesel tank and they accidentally put some gasoline into it. What should they do?


We’ve also seen the converse – one of our customers accidentally put gasoline directly into one of his tractor’s diesel fuel tanks. He wanted to know if it was going to be a problem.

If you deal with fuel long enough, you’re going to come across this kind of situation at least once. Mixing gas and diesel is never advisable, but isn’t necessarily a disaster. The biggest factor is how much of each you accidentally dropped in. Here’s what you might expect if it happens to you.

Big Differences Between Gasoline And Diesel Fuel
When we talk about diesel fuel here, we’re talking about #2 diesel fuel – on-road or off-road, it doesn’t matter.

When you’re trying to predict what kind of issues might arise from accidentally adding one to the other, you have to take into account the biggest differences between the two fuels.

Diesel fuel is heavier than gasoline (because it’s made up of large molecules). It atomizes differently due to a different density and viscosity. And its flash point and autoignition temperatures are significantly higher. And given these, the converse can also be applied. Gasoline is lighter and flashes at a lower temperature than diesel.

Putting Gasoline In Diesel Fuel
Let’s say you accidentally drop a small amount of gasoline into your diesel fuel. The first thing it’s going to is depress the flash point of the diesel, which can be dangerous given that pockets of higher concentrations of gasoline can develop in a tank. So the flash point wouldn’t be consistent throughout the entire tank.

Given the large difference in flash point temperature between gas and diesel, it doesn’t take very much gasoline to depress the flash temperature significantly. As little as 1% gasoline contamination will lower the diesel flash point by 18 degrees C. This means the diesel fuel will prematurely ignite in the diesel engine, which can lead to engine damage.

Gasoline contamination can also damage the fuel pump and mess up diesel injectors. This happens because of a drop in lubrication. Simply speaking, gasoline is a solvent while diesel is an oil. Diesel has enough lubricity to lubricate the fuel pumps and the injectors. Swapping in some gasoline takes away this lubrication, leading to damage.

Beyond these, you’ll get incomplete combustion, initially characterized by large amounts of black smoke. Beyond being an aesthetic problem, the vehicle’s computer will try to compensate for this combustion lack by adjusting the fuel-air mixture. This is going to cut your power and performance considerably. And if you continue to use the fuel, you can cause real damage to the vehicle’s computer sensors by either overheating them or covering them in soot such that they can’t detect anything"

https://www.bellperformance.com/blog/accidentally-mixing-gasoline-and-diesel-fuel

 

Maybe the same reason Coffee Bubbles in low pressure weather systems, viscosity.

That's my guess. A wild one.

 

First you say:
"The tanks were almost empty, so in the tanks were mostly gasoline. Started the truck and after 5 minutes, the truck started misfiring and we saw big bubbles in the fuel filter screen. The engine shuts off"

Then you say:
"I know all of this........ damage DID NOT TAKE PLACE, BECAUSE THE GASOLINE NEVER REACHED THE ENGINE."

So which is it?

My best guess as to why you saw bubbles is that the truck was shaking so bad it was vibrating the fuel bowl.

And dont think for a second that "damage DID NOT TAKE PLACE".

 

Glad you know everything. Maybe you can help the original poster with their problem then?

 

That pretty much tears it now does it not?