I've put a mist of water into the carb before to break loose carbon. Common sense says the cold water will bust off the carbon buildup. Just don't put to much, obviously.
This 5.0 I put it into is fuel injected, 165,000 miles on it, really weak. It is due for a rebuild, wore out. It has been setting for 2 years because the timing chain jumped a cog, and I just put a new timing chain and gears in it. It seemed to make a little more power than it had before, but hard to tell since it had been 2 years since I last drove it. I ran two tanks of fuel through it, then put the Seafoam in it. It now has enough power to spin both back tires (it has a locker) in the gravel. It would barely spin in the mud before. I also put 1/2 a can in the engine and 1/2 in the fuel tank. The fuel system probably needed it the worst, but it is also carrying more oil pressure on the idiot gauge now too. Sounds too good to be true, but I am a believer, for high mileage rigs anyway.
