Hello , I've got a 1989 Totota 4 runner w/ the 3.0L V6 w/ a 5 speed and 270000 mi on the clock. The truck runs great but when I took it in for a smog test, the fast idle was too erraticand the truck would not hold the fast idle for the test. The idle surges at anything above 2000 - 3000 rpm when cold and 1500 -3000 when warm. the truck runs fine and will rev up just fine, but if you rev it slowly it surges at 1500 - 2900 rpm and then will rev up from there till red line.I cant find a vac leak any place,the air box has been replaced with a K & N unit. I am stumped the coil looks fine and the distributor has no excessive free play . The cap and rotor are new. Any Ideas are welcome.