Hey guys and gals!

I have a 98 EK hatch with a JDM B18C type R swap in it. As the type R is known for, I'm having idle issues.

About a week ago, I ported the inlet on my intake manifold to match my Skunk2 70mm throttle body that I had laying around. After re-assembling everything, my idle was around 2,500 RPMs.

Hoping that it was my TPS (since I was throwing a CEL for the TPS), I back probed the sensor and set the TPS straight. The idle was still around 2,000 RPMs.

Wondering if there was a vacuum leak somewhere, I sprayed flammable brake parts cleaner all over the place. The idle didn't change once, so I'm going to assume that there's no vacuum leaks.

I got the car tuned as is, and I had my tuner set the idle a little lower. The car still idled around 1,700 RPMs.

With the car idling at normal operating temperature and the intake off, if I put my finger over the hole inside of the throttle body that leads to the IACV, the car idles fine.

I cut a piece of aluminum for an IACV block-off plate and I mounted it underneath of my IACV, using the IACV itself to keep the aluminum mounted in place. The idle is a little bit lower yet, but it's still around 1,400 RPMs, so I'm assuming that my block off plate is leaking a little bit, unless having the IACV on top of the piece of aluminum is causing a vacuum leak through the IACV.

I want to completely eliminate the IACV, but I'm not quite sure how to do so besides the way that I've already done it, which obviously didn't work all that great.

Could somebody who has been through this experience walk me through, step by step, deleting my IACV for good?

Thanks in advance!

- DJ

 

Never heard that the type r was known to have idle issues....


There is a iacv block plate that completely removes the iacv from your engine and covers up the two holes, you'll still need to use the gasket around the holes.

 

Where do I get this plate from?

 

#whenDIYgoeswrong


check the throttle cable/next check the butterfly plate screw it will be very small and kind of hidden on the tb. simply adjust it till the idle lowers.

 

#WhenPeopleAssumeIDidThingsWrong

The throttle cable is loose as it is and the throttle plate screw is unscrewed too far in my opinion. Far enough as to where it seems to actually stick closed a little bit.

 

When I swapped to a 70mm to on my c27a4 and port matched and polished the im, afterward I had a vacuum leak causing a high idle around 2000 rpm and in my case I ended up having to make my own gasket using material from the parts store. Did you set the idle with the car warm and iac unplugged? I believe it's 650-750rpm with no accessories and iac disconnected, tps at .45-.50 at closed throttle

 

Almost forgot that the instructions I read said to remove the main relay or disconnect the battery for a minute or so after adjusting everything so the ecu can relearn all the changes. Hope that helps

 

VAC leak then...you answered it your self, you just have to find it

 

I've searched high and low for vacuum leaks, as did my tuner. Numerous cans of brake cleaner used. Didn't find anything.

 

what happens when you put your bare hand on the tb bore?

 

Do you mean over the IACV hole in the throttle body?

 

If your tuner has access to a smoke machine that would be ideal, I tried flammable brake clean as well as throttle body cleaner and neither reacted with my vacuum leak, and mine was almost the whole side of the tb gasket...felt pathetic it took me 20mins to find it

 

The whole bore....if it doesn't stall you definitely have a prob

 

I'll try putting my palm over the TB bore tomorrow since I'm at work for the night. I don't think he has a smoke machine, but I may know somebody who does.

Could you explain to me how and where I would hook up the smoke machine?

 

There are adapter caps that block off the tb bore with the intake tube disconnected, from there it hooks up to a vacuum line using a cone shaped barbed tip. I prefer using the line that goes the the brake booster. Anywhere there's a leak smoke will come out...works best indoors with a good flashlight or spotlight

 

You could also find a friend who smokes (cigars, pipes, or....whatever, cigarette smoke won't be thick enough), and have them exhale on your running motor. You'll see the thick smoke getting sucked in somewhere.

 

Indeed, I didn't want to say that out of fear of getting bashed, but I have seen that method work.

 

Thank you guys. You've been a great help!

 

I know what line that you're talking about coming off of the brake booster, but will putting smoke in that line run the smoke throughout the whole vacuum system?

 

Although crappy vids, they give you an easy idea on how to make a simple smoke tester. Jusn an fyi, we use baby oil on our smoke machineat work, so you can use that as your source too.

 

forgot all about smoke tester/machines...despite learning that in school last year.

+1 even just going to a shop to get that done and watch, I remember seeing it in class was really impressive how accurate and fast it was.