GQ Patrol idle flucation

Thanks Pastie, I realized Tourboy must have been talking about a petrol engine when I tried to find a throttle butterfly on the nissan. I suspect you are right and the idle up pump? may have an intermittent problem as the old girl will generally idle normally and increase revs when a/c turned on . However sometimes when city driving and I pull up at the lights and put auto into neutral, no aircon on, the revs slowly increase to approx 1000. Makes for a jump start when I put it into drive.