ok, I have a 68mm TB from Skunk2 on my H22. According to skunk it's normal for it to not idle well when cold. They say it's just a trade for performance since its designed for racing. I get that, but mine won't idle at all. It starts, then dies immediately.

I noticed that the air bypass hole on the skunk is about a quarter the size of the one on the OEM TB. Is this why it has idle issues? if so, can the bypass passage be bored out to fix the idleing?

Thanks!

 

Throttle cable too loose maybe?

 

does the Skunk TB use a FITV?

 

no, and because of that I can understand it idleing odd, but before I had the Skunk I had my OEM FITV blocked for years and it would still idle. So it seems that while that might be a contributor, that's not the entire problem.

Once the car starts to warm up everything is fine, it idles at 750 or so with no problem.

In a couple months this probably won't matter since it won't drop below 80 at night, but for the time being it's annoying. Not life or death by any means, just a nuisance.

 

Mate, I have the exact same problem on my build using a Skunk2 68mm TB. The idle air bypass hole is tiny compared to the OEM TB. We looked at drilling it out a bit bigger, but it doesn't appear to be a straight hole through it i.e. it's drilled from two seperate angles from either side.

As a temporary get-around, we've had to remove the bolt from the bottom of the throttle body (where a sensor can be mounted I believe), and run without it. This at least gives it an alternative source of air when the manifold is in vacuum at idle

 

do you mean the idle adjust screw?

 

No, there is a big bolt on the bottom, something like an M8 bolt or something, with a rubber O-ring. We pulled that, and it seemed to at least allow the car to idle by itself. Not ideal I know, but a temporary get-around.

 

well I guess that verifies my original theory. Now to figure out how to open that up. I know I could drill most of it from the back, but you're right about it having an angle to get into the chamber on the intake side of the throttle plate. Not sure how I would do that part. I might just take it into a machine shop. I'm not sure using a hand drill is the best idea anyway. lol