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Discussion Starter #1
I made an appointment to get my car tuned at MAP here in mn, took it in no problems blah blah blah after an hour of waiting for them to strap it to the dyno jordan (the tuner) comes and hands me a list of shit i need to fix or replace and yeah my setups not the best by any means but im effin 18 and need a car to get to school in arizona.

He said he wouldnt tune the car without a functioning iacv, I also called full blown and asked them and the first time i called they said tthat they could do it no problem its just a pain and then called back then the guy said he couldnt.
Nick (the scheduler) at MAP said they could tune the car also it is just a pain.

so my question here is do i really need an iacv or am i just getting hosed?

my understanding is the iacv just has coolant running through it and just controls idle, jordan told me it will cause surge or can cause surge????
 

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1991 Honda CRX
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It's an electrical solenoid to control idle, the coolant lines are just for during cold months so it doesn't freeze over. It most likely just needs to be cleaned, there are a lot of threads on cleaning them out. They are easy to swap out so it shouldn't be a problem. Did you delete the IACV? If you did, it won't cause it to surge but it can cause engine damage from high vacuum during deceleration. Just put on on if you don't, you don't have to hook the coolant lines up just the plug for now.
 

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you need the IACV working perfectly if you want your car to be streetable. the ECU uses it to allow additional air when various electrical systems demand more airflow. without it, you will have an engine that feels like shit and keeps bogging down everytime the AC compressor or radiator fans or headlights, etc. kick on. clean up what you have or buy one off eBay. they go very cheap.
 

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Meat Popsicle
91 CRX Si
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Is it surging now?

When you rev the car and then let it idle, does it shake and feel like it's going to stall before it idles normally?

Abnormally low idle?


If it doesn't do any of the above then it sounds like your IACV is OK. I would, however, say that it is pretty damn important to have a working IACV
 

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Discussion Starter #6
ok i have a 95 sedan and a d16y8 from a 97 ex, fully built, the car has the one iacv underneath the throttle body but i cannot find the plug for it, because if i remember correctly the iacv for my d15b7 i had was on the back of the manifold and was only a 2 wire plug and this one is a 3 wire plug. the engine is also from a automatic so i would have to swap intake manifolds and im out of money for this car and thats kinda my last option at this point, and junk yards in mn are expensive for civic parts.

the car also does not surge it stays just at or just under 1000 rpms and when i rev the car it drops to 500 then back to 1000 and stays there. and the only cel i have is a cel 10 and that is for iat.

i am also going to be living in arizona so i figured the iacv wasnt as important. aslong as it idled it would be good to go...

with all this said i also am going to be daily driving this car for school but i dont care if it idles rough or not i just want it to run and be somewhat reliable at this point
 

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since the Y8 is from a automatic the intake manifold is not drilled for a IACV. there is a way to run a IACV without having it on the manifold though. i will see if i can find a write up on it somewhere, had to be done on my friends old ls/v with a venom (shit) IM with no IACV holes
 

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Jordan has built quite a reputation for himself. I am not insinuating that your car is hacked at all, however it is not in his best interest to have his name tied to a car he feels needs a couple things.

Just my .02...fix w/e he says needs to be done and go see him. He is the best tuner in the area hands down. He tuned my friends 800+ hp b18c1, at least 1 1k+hp evo, and another buddies 450+hp cx hatch.

The guy has been tuning a long time and tuned a ton of hondas in the ND, SD, MN, IA and WI area.
 

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I have no IACV(stock ECU) and my car has no surge, and idles fine. I do have a FITV thou.




You can drill and tap the auto manifold and install a IACV
 

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Discussion Starter #15
i know jordan knows his shit and i replaced the stuff i know needed to be replaced.

im just looking to daily drive this car like i said before and im not looking for it to be a record breaking track car, i just wanna drive it and know it wont blow up.
 

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if that were the case, there would be an idling speed drop on a warm engine when the AC compressor kicked in yes?
well in general, once you turn on the ac id assume the ecu kicks some voltage out to the iacv and idle goes a bit higher. ive never had ac in any of my cars my entire life so i wouldn't know lol.

all i know is if you measure voltage at cold start it drop slowly and the iacv the closes shutting the air passage from the tb
 

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94 Integra
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The IACV is just an electronic air valve, letting more air into the engine to modulate RPM. It's there for a reason. As that DIY IACV relocation thread shows, it's easy as sin to have an IACV.

It controls rpm during: COLD idle, MOVING idle, NORMAL idle, when the power steering pulls a load at idle, when the AC pulls a load at idle, when the engine decellerates to (and below) intended idle speed, and a few more I probably don't know about.

You can get by w/o it, but there's really no benifit. It weighs half a pound at most, and isnt' hard to fit onto a 2-wire ems that has a 3-wire intake manifold.
 

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well in general, once you turn on the ac id assume the ecu kicks some voltage out to the iacv and idle goes a bit higher. ive never had ac in any of my cars my entire life so i wouldn't know lol.

all i know is if you measure voltage at cold start it drop slowly and the iacv the closes shutting the air passage from the tb
the ECU controls the IACV using a PWM signal at approximately 400 Hz. simply connecting a DVOM to check voltage across the wires will not give you any useful information. one needs an oscilloscope for that.
 
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