Mazda Repair: Idle surge when cold, air leak, control valve
Question1992 MX-3 with V6, 5 speed
My car has begun to surge at idle until fully warmed up. Th revs will keep going up and down between about 300 and 2500. Once the engine is warmed up it acts normal. Anything I can do myself to fix it?
AnswerHi Anne,
Unfortunately there probably isn't anything you can do yourself to fix the problem. Since you haven't told me whether your check engine light is on or not i'm going to assume its not. Therefore the most likely problem is an air leak in one of the hoses connecting to the ISC Valve (Idle Speed Control Valve). The valve itself could also be faulty and/or dirty.
hope this helps