yeah i need help figureout whats the problem with my b17vtec.no mods just stocks.i recently replace the iacv.today when i was drivin came up to a stop suddenly my rpm just drop to 1000rpm then back up to 2000rpm keep doin this rapidly.i'm guessin is my thermostate??can this be?let me what ya'll think it is?

 

https://honda-tech.com/forums/acura-integra-6/creating-new-topic-choose-subject-specific-title-not-help-me-asap-2477272/

 

It sounds to me like there are a couple possibilities...

1. You have a vacuum leak. You can find this by spraying carb/throttle body cleaner over vacuum hoses and in gasket areas around the intake manifold. If the rpm changes when you spray over a spot, you found where the leak is.

2. Something is wrong with your fast idle thermo valve. Search "FITV" and you will find a ton of info on cleaning and adjusting it.

3. There could be air bubbles trapped in your cooling system from when you changed out the IACV. Did you bleed the system after you changed it? Air trapped in there can give screwy readings to the coolant temp sensor causing the idle to jump around.

 

sounds like a vacuum leak to me, i would use the carb cleaner or propane to pinpoint its location. check the FITV for sure as seanbev24 said.

 

no i just replace fitv but did not bleed it.when i park my car while engine is hot.i check both the rad hose the top was very hot feelin,bottom was not.so i'm thinkin is the thermo not openin up....and possible vacuum leak.i look at whats goin on.

 

In your first post you say you replaced the IACV, but your last post you say you replaced the FITV. Did you replace both or are you getting them confused? The FITV is under the throttle body, the IACV is on the backside of the intake manifold.

Air trapped in the cooling system can cause a blockage of flow that acts like the thermostat isn't opening. This would also most likely cause you to overheat. What does your temp gauge do when the surges are happening?

It still sounds more like a vacuum leak to me. Did you use new gaskets when installing the IACV and/or the FITV? Are you sure you didn't knock a vacuum line loose or forget to reinstall one?

 

yeah..i meant the iacv was new.no i have'nt touch the fitv and disturbutor yet.like i said after it warm-up the idel just drop from 2000rpm to 1000rpm repeatly.even when i drive it and pop it in neutral still gets same result.i already check cooling system and vacumm leak seem to be ok.i'am seein a lil leak on the head and block..can this cause it to flucuate idle?

 

to start off bleed your coolant system...second double check all or your vacuum lines...third clean your FITV...if that fails sell your car...no just kidding keep us updated

 

woohoo!!i got to them FITV.clean it up with carb cleaner put everything back.crank th G-up..nomore flucateting.keep doin wut y'all do!!thats wuz good!!nice write-up on that link too.