unstable idle

quarkhimself · Post by **quarkhimself** » Tue May 20, 2014 11:44 am

hello guys, first of all i am sorry if there's already a thread on this subject, i did search but i was unable to find it. and again i'm sorry if this is not the right section, but here it goes.
i recently changed the spark plugs and spark plug wires and cleaned the throttle body. yesterday i was cleaning the trottle body , put everything back together, turn the ignition on and everything was fine. this morning when i turn on the ignition i noticed that the idle was going from around 700rpm to 1500rpm. it's like it goes to 1500rpm then drops to 700rpm, goes back and then back down and it keeps doing this. what can be causing this ? any help would be very much apreciated.
by the way, it's a 4th gen si vtec JDM, engine h22a.

Post by **Merlin** » Tue May 20, 2014 11:48 am

Does this happen while the engine is warming up or once the engine is warm? When it warming up the problem is commonly the FITV. If it occurs once the engine is warm it is most likely the IACV.

How to sort your FITV - http://www.ludegeneration.co.uk/honda-p ... -t758.html

quarkhimself · Post by **quarkhimself** » Tue May 20, 2014 11:54 am

Well it happened when i first drove the car this morning, so it happens when it's cold.i drove for 10 minutes or less, went shopping, got back to the car it happened again, drove home for 10 minutes and when i parked the car it was still happening. Im thinking it may be some kind of air leak or something ? Maybe i'll take the throttle body out again and put it back together to check if i missed something.

quarkhimself · Post by **quarkhimself** » Tue May 20, 2014 11:57 am

Merlin wrote:Does this happen while the engine is warming up or once the engine is warm? When it warming up the problem is commonly the FITV. If it occurs once the engine is warm it is most likely the IACV.

How to sort your FITV - http://www.ludegeneration.co.uk/honda-p ... -t758.html

Thanks Merlin, i'll have a look at this. Thak you very much for your quick reply!

Post by **Merlin** » Tue May 20, 2014 11:57 am

The FITV is on the bottom to the throttle body so you may have knocked something off or split a hose or something. I'd wager it is FITV related.

Post by **vanzep** » Tue May 20, 2014 11:58 am

yep - cleaning and resetting the fitv cured my bouncing idle

quarkhimself · Post by **quarkhimself** » Tue May 20, 2014 2:16 pm

ok so i got the throttle body out again, but i wasn't able to get the fitv off the throttle body. it seems that i need to take 3 bolts off, they're really stuck and i'm afraid to damage them. it looks like they're 10mm, right ? i dont know why but the wrench kind of slips and i dont want to round them off. what should i do ?

Post by **Merlin** » Tue May 20, 2014 2:23 pm

Yeah it should be 10mm but if it is slipping you could try and see if an imperial size fits it a bit better. I have a set of gripper sockets for problematic nuts.

quarkhimself · Post by **quarkhimself** » Tue May 20, 2014 2:50 pm

good idea, merlin. i'll try that an i'll let you know how it goes.

Post by **SPYDOR** » Tue May 20, 2014 2:58 pm

Maybe spray the bolts with some good penetrating oil a few times, like Plusgas for example and leave to soak for a few hours. Make sure you use a 6 sided socket, as 12 sided is more likely to round off.

When you get the FITV apart and give it a good clean up, you are meant to screw it all the way in, then back it out 3/4 of a turn apparently. I did this on mine recently and it stabilized a few idle fluctuations. I also cleaned a lot of limescale out of a few of the passages, which suggests the water in my coolant system had been filled with hard water at some point, instead of distilled.

Other point I will mention is the wax plunger and seals go in much better when they are cold. I did mine outside on a hot day and could not thread the plunger back in, however 20 minutes in the freezer and it threaded back in very easily.

Lude Generation

unstable idle

unstable idle

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