I still have an idle surge on my b20. It surges from about 2k to 1k. I have checked all obvious signs. (fitv is tight, just cleaned iacv,did a valve adjustment) I dont know where to look now.

 

clean your fitv

 

What do you mean by clean it. I have had this problem before and all it took was a quick screw driver to the inner wax of the fitv. But this time when i went to do it, it was set in there tight.

 

You take the fitv off, open it, spray it with throttlebody cleaner, or brake cleaner, then take it apart, clean it, put it back together...

it fixed my problem and mine was worse then yours, 2500 idle/ surge'd from 1800-2500 constantly..

here are some threads on how to do it

https://honda-tech.com/zerothread?id=1564019

https://honda-tech.com/zerothread?id=699787

 

Thats how mine used to be, but luckily its only 2k but its still annoying. Alright. Ill try that in a little bit.

 

Ok...didnt fix it....

 

Sounds a little like a vac leak.

 

if it keeps surging up and down and you cleaned the fitv then your tsp sensor might be bad, mine did the same and i replaced it and stopped surging...

 

Alright heres a quick link to it.. dont mind the stupid indiglos... It only does this when it gets warm..
http://smg.photobucket.com/alb...5.flv

 

Do you really think a tps or vaccum leak would cause a surge that quick?

 

thats exactly what mine did and i was told to replace my tps sensor and i did and the idling problem stopped, only problem was the sensor is rivited onto the throttle body and the dealer told me i could only get the sensor if i bought the whole throttle body, so i drilled one off a civic at a junk yard and put it onto mine...

 

Dont you think id be throwing a cel for that though? Thats quite an expensive fix..

 

Any input?

 

now that i think about it, yah, mine did throw a cel and when i got it checked was how i figured out what was wrong...

 

Yo my B16 did that same thing and I found a vacuum leak, I fixed the leak and that fixed the surge problem. I think you should check for a leak

 

I'll look for leaks today. When i unplug the wires on my iacv it idles normal..if that helps.

 

Come on i know someone knows the answer. Spread the knowledge

 

Could be a number of things. Maybe air bubbles in the coolant system? Bleed the system and see what happens.

Bad tps (if you have a multimeter you can test this quite easily) and if it IS a bad TPS, you can just put a different one on. The screws holding it in are "bare" on top, so you'll have to cut a groove into them (I used a hacksaw, worked like a charm) and they will twist out.

Definitely could be a vacuum leak, those are always fun to try and find

I had this same problem, but mine was due to running the stupid 99-00 y8 IM on a z6, had to seal off some air ports, this probably isn't your situation though..

Good luck!

 

This is amazing...ive done everything suggested and still nothing

 

Up for some help..

 

i had this problem once read that the fitv controls cold idle and the iac controls it when warm, i thought i had a bad iac because my car would surge once warm also after i did my swap but i actually had the ait sensor and iac plugs switched. not sure if this may be your problem but some suggestions for you

 

Thanks for the help. It pretty much only does it when its warm..but it idles high cold. I dont think anythings switch because this came out of no where.

 

look and listen very closely for a vacuum leak, broken vacuum hoses, unplug vacuum ports and so on..

 

eh i got the same problem with my civic..i got a GSR in it and when i start it it revs to about 2500 and slowly goes down to about 1800 but then up agaian and this keeps repeating..but than after abotu 10 mins..it idles regular at about 900...
ne one think of anyhting?

 

If you unplug the IACV, the idle should drop to ~550rpm...which is not a 'normal' idle speed. So if it's dropping to 750ish rpm when the IACV is unplugged, you either have a vacuum leak or the base idle is set to high.