The 262 in IL2 is very difficult to manage.
It takes to be very tactical and forget about arcade play, you should NEVER be so slow to extend slats in combat!
Use joystick like the wheel of a car when driving on ice, always sweet and never sharp.
Here is some advice for a typical mission from a guy who is an 'online experten' on the 262 (curiously his nick is 'meteor')
0) always load 100% of fuel
1) select left engine
2) swith on left engine
3) unselect left engine
4) wait 10 seconds;
5) select right engine;
6) swith on right engine
7) unselect right engine;

select all engines
9) wait 10 seconds, while you set flap on landing
10) VEERY slowly bring throttle to 100% whlie holding brakes (B)
11) release brakes, take off and fly straight at low level (do NOT climb or turn now)
12) close gear and flaps, at 280 Kmh reduce throttle to 85%, always fly straight and low to build speed
13) at 400 Kmh bring throttle to 90%
14) at 500 Kmh bring throttle to 94% and start climbing sweetly, try to not lose speed. You gain height with speed, not with AoA
15) in cruise hold 94% throttle because above 95% you trail smoke and you may be spotted (if flying online, of course) use 100% only when it doesn't matter if they see you (i.e. when you press the attack)
16) take your time to pick and destroy enemies, do not hurry. Nobody can attack you as long as you maintain speed. Never turn, if you miss the 'boom' just extend, regain height and go for another run. You are at risk only if you lose speed.
17) in landing approach keep speed to about 200 Kph and never go under 10% throttle (you may flame out)
hope it helps