[redvitara]

Gday all
Recently I reconditioned the motor in my '95 lab vitara.
All's good with it (much stronger, better economy & uses no oil now) except for an erratic idle. Sometimes it will idle properly at around 800rpm, other times it will drop to well below 500rpm & slowly work its way back to 800rpm. The a/c does raise the revs to about 1000rpm. When starting the car from cold the revs never go above 1000rpm.
I have changed the IAC unit & when I test it by putting 12v across it it does open up.
Has anyone else had this problem & can point me to a fix.
I'm thinking its a faulty sensor or possibly coolant flow to IAC?
Thanks
Redvitara

[Reubs]

Vacuum leak? I had similar symptoms caused by a faulty pcv and pcv seal.