Triumphrat

tigerwilson · 11-12-2007

Hello, I have a 2001 S3 and being new to this bike, while I was doing a valve adjustment, I removed the idle air control unit, thinking this unit was tied to the clean air unit, which the prior owner removed. I cut a piece of plastic the shape of the idle air control unit and epoxied it and blocked off the hole in the air box and capped off the lines going to the throttle body. Now I realized this unit actually controls the idle from start, and possible more. I'm totally new to the bike, so I'm not sure how it started before, but now I hold the rpms around 2k to warm up the bike. Can anyone explain what this unit does and I'm assuming I should reinstall it. Anyone can tell me how to reassemble it, I have it in pieces, consisting of white piston, spring and black metal spacer. Does it go white piston, spring then black metal spacer, OR white piston, metal spacer then spring......

Thanks!

dr_gallup · 11-13-2007

Wow, that is the first time I've ever heard of anyone doing that. You should definitely put it back on. It controls idle speed by changing the amount of air that bleeds around the throttle valves when the throttle is closed. You are going to have all kinds of problems with stalling & idle speed without it. Can't help you with putting it back together.

tigerwilson · 11-13-2007

Not sure about all the problems, it seems to run and idle fine once its all warmed up. From what I can see, the mechanism moves a piston up and down, when its down it allows air from the airbox to the throttle body, and when closed, its essentially blocked off. I plan to put it back on, but was curious if the piston is moving up and down based on various operating conditions, or just at start up? To me it feels just like starting a bike without using the choke, you can do it, it will require holding open the gas a bit to keep idle, but once warmed up, it runs fine.

Anyways, I need to order a new o-ring seal, and then its back on the bike.

DRJONES · 11-14-2007

I would consult a manual and/or microfiche to look at the ISCV is constructed

dr_gallup · 11-14-2007

I'm not really familiar with the earlier systems. How is this controlled? On the newer systems it is continuously variable valve actuated by a computer controlled stepper motor. Yours sounds like it is just a 2 position on/off device that basicaly gives you a fast idle during cold start. Is it manually actuated by a lever or cable or does the computer control it? If it is manually actuated then you could leave it off, you are doing the same thing by holding the throttle open. The only advantage to putting it back on is you could let go of the throttle while it is warming up.