IACV, surging idle and AFR nightmare...HELP!
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IACV, surging idle and AFR nightmare...HELP!
Here is my issue as best as I can describe it. The motor in question is a turbo B18A.
1. When I start the car the idle surges from 1000-1500 RPM, in general it seems to misfire until around 2k RPM however AFR is solid right around 12 the entire time.
2. I checked for vacuum leaks with butane and found none (when the engine surges up the boost gauge reads -20), however since its surging so much I am not 100% sure Id detect them properly even if one was there.
3. If I disconnect the IACV the engine RPMs drop but continue to surge, and the engine will stall after a few cycles of this.
4. When the IACV is disconnected the car has a HARD time revving at all until it reaches at least 5k RPM. Also, the AFR goes VERY(!) lean when trying to rev at all.
Any ideas on how to straighten this mess out? Im thinking that the IACV might be stuck open. As a side question, does the IACV need to be heated with coolant to function correctly or can I bypass this?
1. When I start the car the idle surges from 1000-1500 RPM, in general it seems to misfire until around 2k RPM however AFR is solid right around 12 the entire time.
2. I checked for vacuum leaks with butane and found none (when the engine surges up the boost gauge reads -20), however since its surging so much I am not 100% sure Id detect them properly even if one was there.
3. If I disconnect the IACV the engine RPMs drop but continue to surge, and the engine will stall after a few cycles of this.
4. When the IACV is disconnected the car has a HARD time revving at all until it reaches at least 5k RPM. Also, the AFR goes VERY(!) lean when trying to rev at all.
Any ideas on how to straighten this mess out? Im thinking that the IACV might be stuck open. As a side question, does the IACV need to be heated with coolant to function correctly or can I bypass this?
Last edited by URNVS; 11-21-2009 at 06:15 PM.
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Re: IACV, surging idle and AFR nightmare...HELP!
you donot need the coolant lines to the iacv, it can be bypassed. i would start by taking appart your fitv,make sure its together right, clean it up and install. same with the iacv if problem persists. sometimes a simple cleaning will do the trick. i had the same issue with my built motor.. the car ran 100% for a few wks after fresh build and wouldnt u kno,out of nowhere i get the SURJE.ended up being my fitv..let us kno how it goes
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Re: IACV, surging idle and AFR nightmare...HELP!
It has a base tune off another car which was very similar to my setup and is running 450cc injectors. It has been able to idle in the past on the same tune.
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Re: IACV, surging idle and AFR nightmare...HELP!
Ive never had it 'completely' running but it did start, idle and drive to different parking spots at the shop...
Last weekend I pulled & throughly cleaned the IACV then tested it with a battery. This did not fix the issues Im having
Last weekend I pulled & throughly cleaned the IACV then tested it with a battery. This did not fix the issues Im having
#9
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Re: IACV, surging idle and AFR nightmare...HELP!
also get the car tuned, a basemap from a "similar" car doesnt mean it will run properly
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Re: IACV, surging idle and AFR nightmare...HELP!
I am planning on getting it dyno tuned but I need it to at least idle so I can verify the timing and check that everything else works first
The engine is obd0 so there is an FITV (thats the one on the intake manifold below the throttle body right?), what is the 'white plastic piece'? Should be apparent if I take the valve off?
The engine is obd0 so there is an FITV (thats the one on the intake manifold below the throttle body right?), what is the 'white plastic piece'? Should be apparent if I take the valve off?
#11
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Re: IACV, surging idle and AFR nightmare...HELP!
https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/
i dont know if you need to completely disassemble it like that guy. just see if its loose and tighten the white piece
i dont know if you need to completely disassemble it like that guy. just see if its loose and tighten the white piece
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Re: IACV, surging idle and AFR nightmare...HELP!
I saw that thread but my car doesnt look like that, it has what is most likely the FITV bolted directly to the manifold below the throttle body.
#13
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Re: IACV, surging idle and AFR nightmare...HELP!
lol how much more directly under the throttle body can it get?
either way, pull it apart and check it out
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Re: IACV, surging idle and AFR nightmare...HELP!
Im going to take a look at it tonight, but on my engine its not mounted ON the throttle body like it is in that picture. #11 in the below picture, Im pretty sure its the same thing.
http://i42.tinypic.com/2guwg37.jpg
http://i42.tinypic.com/2guwg37.jpg
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