Question for mechanics

[Ranger Kip]

Jason is having an issue with his 2003 Ford Focus, it is having trouble starting more recently, and has been reving up on idle and while driving.

We have heard of this happening, but we are clueless to what can cause it.

Now, this car is in EXCELLENT condition, its just that it'll rev up every 2 or 3 seconds and then repeat that cycle until we shut it off.

If you turn on the A/C it'll get worse.

Ideas?

 

[pontiacfieroguy]

sounds to me like a vacume leak. there is a horse shoe curved black plastic like one the passenger side of the valve cover that are notorious for getting brittle and breaking.

 

[LearjetMinako]

Could be a vacuum leak or a sticky IAC (Idle Air Control). RPM surges are suppose to happen with the A/C on. It counter balances the extra sudden load placed on the engine to mantain a constant level RPM (the PCM learns the correct amount to give). Thou if it gets worse, I would suspect the IAC as its the main component that controls that RPM surge. Simply remove it and spary it clean with a carb cleaner.

FYI: If it is the IAC, don't get one from Autozone if decide to replace one. They suck and are mostly not of OEM design. Have had that problem before

 

[Ranger Kip]

alright, thanks, be sure to tell him!