Idle surge is making me angry!

[coletrain]

alright, Iv'e had this idle surge problem for a long time now. It's starting to piss me off.
Here's the problem: it revs up to 2,000 rpms and back down to normal idle over and over again. And sometimes it'll go away once the car has been running for a while. The idle surging is 10x's worse in cold weather.

I took it to the shop, they checked everything, replaced my thermostat b/c engine temperature was off. I had my coolant flushed and refilled. I cleaned out the IAC valve and FIV valve on Intake Mani. What else is there?

All the engine has is a short air intake. PLEASE HELP!!!!!!!

[Ralphie]

o2 sensor...seen it bunch of times. maybe mafs.

[coletrain]

mafs?

[h22sparkle]

Vacuum leak any trouble codes? I say you got a vacuum leak start pinching hoses dude.

[Ralphie]

mass air flow sensor....yea vacuum leak would make sense too. There was crx with a b16 swap that my dude owned not too long ago and once he sold it whoever bought it had this same problem with the rpms fluctuating from like 750+/- up to 2000+/- and then back down again and repeating and yea on rev or warm up it would cease but then come back again.

[Ralphie]

mass air flow sensor....yea vacuum leak would make sense too. There was crx with a b16 swap that my dude owned not too long ago and once he sold it whoever bought it had this same problem with the rpms fluctuating from like 750+/- up to 2000+/- and then back down again and repeating and yea on rev or warm up it would cease but then come back again.

oh ya turned out to be an o2 sensor.

[coletrain]

where's the mafs located
and where are the o2 sensors located that you metioned

[NAiL05]

We dont have a MAF we have a MAP if i remember correctly. O2 sensor is located on the downpipe. Another easy way is to spray around where you might suspect its leaking with like water or something and listen for engine tone change and that would be where your leak is.

[TysCb7]

Vacuum leak any trouble codes? I say you got a vacuum leak start pinching hoses dude.

...I'm going with sparkle on the vac leak, could also be a bad tb or intake mani gasket.

[92ex]

We dont have a MAF we have a MAP if i remember correctly.

word. Think about it, mass air flow, sensor on intake, manifold absolute pressure, sensor to intake manifold. Which one do we have

[KillerCam282]

MAF? O2 sensor? OMG, why...why...why...

FIV and IACV cause shitty idling on F22 equipped hondas. I can tell you very confidently that the MAF and O2 sensor have absolutely nothing to do with this problem. Based of their jobs in the engine bay, there is no way they can even cause this problem. Another cause is having too much air in your coolant system. Replace both and bleed the coolant system, problem should go away. Its very,berry rare that it doesnt after this. in those instances its a damaged vacuum hose. Spray hoses with water (lightly!!!) and inspect for holes. Best culprit in case of a vacuum leak is the Brake booster vacuum source.

[f22-dohc]

any coolant leaks??

[laz93se]

x2 on the vac leak pinch all the three main hoses leading to the map sensor one by one and check if they have been placed in the wrong hole.peace

[d112crzy]

vac leak or tighten down that screw thingy in the fiv(if u havent done so)

[KillerCam282]

Cleaning the FIV and IACV...I am not sure that even works. Try new ones all together. Maybe on the FIV, but I don't think it will on the IACV.

The vacuum lines are cheaper to check. Inspect those first with the engine running.