4kq lumpy idle

[Greg East <gregeast@frii.com>]

My '86 4kcsq has had a poor idle for months now. The idle is lumpy at rest
and will nearly stall when the revs drop when pulling up to a stop light,
etc. Now that it's getting warm in Colorado again (finally), I've noticed
that the idle is fine when the A/C is on. 

Does the fact that the idle's ok when the A/C is on give anyone any ideas on
where the problem lies?

TIA

Greg East
Loveland, Colorado
gregeast@frii.com