Malleus
Far west of Siegen
I don't know how that could help the engine stumbling problem. The fuel rail and the fuel pressure regulator are cold by virtue of the fuel in them. Put your hand on either while the engine is running. I think it's more likely your leaf blower is doing the same thing your driving is: cooling the radiator.
You can try something similar: get a 1-gallon garden sprayer and fill it with water. The next time the engine stumbles, spray the radiator and see if it improves. If it does, your fan clutch needs new oil:
Much cheaper than a new fan clutch. Amazon will get it to you tomorrow. The whole job takes less than an hour.
Fan clutch mod, Post #1-5
See post #1
Did you test your thermostat? If you didn't you can't know whether that was actually a problem.
I'm still betting on the fan clutch.
You can try something similar: get a 1-gallon garden sprayer and fill it with water. The next time the engine stumbles, spray the radiator and see if it improves. If it does, your fan clutch needs new oil:
Much cheaper than a new fan clutch. Amazon will get it to you tomorrow. The whole job takes less than an hour.
Fan clutch mod, Post #1-5
See post #1
Did you test your thermostat? If you didn't you can't know whether that was actually a problem.
I'm still betting on the fan clutch.