Hey guys relatively inexperienced tech here but I know enough. I just finished putting a new factory engine in my ranger. Between the new motor and the suspension work the fuel that's been in the tank has been there for a little over 2 years give or take. I just go the new motor primed and ready to start and I gotta admit I'm a little impatient to fire it up but I'm hesitant with the state of the fuel. Truck has new injectors now but I'm just curious as to if it's a bad idea and how bad of an Idea it is to fire it up like that. Thank for any help

 

As long as you have a fuel filter on it it won't hurt anything but probably not alot of "burnable" gasoline left, gasoline evaporates, if the gas cap has been on the whole time that will help
All gasoline has water in it, and gasoline won't mix with water
Water is heavier than gasoline
So after sitting for so long there will be a bit of water at the fuel pump, so the first bit if fuel will probably "pop" a bit because of the water
"Bad gas" is gas with too much water in it, lol

But no harm in starting it up, if you can
I wouldn't try and diagnose a running issue with new engine with current gasoline in the tank, that would be a waste of time

You could add a can of HEET or Octane boost to whats left in the tank, or fill it up with new gas that has 10% ethanol, to mix with the old gas
Ethanol bonds with water, so it can be burned, not much power but no "pops", and it also increases Octane level in old gas

 

Thanks I appreciate the help