Arnie, with injection you should use the shutoff valve to lean it after it has started. To build heat I inch it out until I just hear some popping in the exhaust, that is close to stalling it, and usually gets me 2500 rpm. I use a cable from a semi truck that I can rotate the knob for a very fine adjustment, its really handy:

http://www.awdirect.com/exterior-throttle-cable-15-foot-control-cable-vcgtx15/throttle/