haha, seriously I'm trying to think out a quick and easy response but it's not working.
It basically comes down to the 2 different fuels and 2 different ignition types. Gas engines require a certain stoichiometric ratio to product the optimium amount of power. With no throttle plate you couldn't control the amount of air entering the engine and you wouldn't be able to control the RPMs without starving the engine of fuel and creating a lean hot burn(which will eventually result in a misfire). Diesels however naturally draw in much more air than they need to burn the fuel and don't lean out like gas engines do because of the low volatility of the fuel. Basically you add fuel to add RPMs
You may be better off googling diesel vs gasoline engines. I may not be explaining it totally accurately
edit - and also my grammar sucks when I'm trying to sound smart
Last edited by sinner6.0L; 03-08-2012 at 05:24 PM.