coderighter

Blogs and forums, not technical documents. Tell you what, you're listed as a Electronic Engineeer, do this. Apply 12v to the PAIR valve, you'll notice it allows air to pass, remove the 12v and the valve will block the air flow. Now we know that to operate the PAIR, the ECU supplies 12v to the valve. Now start the bike cold and measure the voltage at the PAIR connector on the bike and you'll notice 12v present, meaning PAIR is active. Now keep measuring while slowing taking the throttle off idle and you'll notice as soon as you get off the throttle stop, the voltage goes to zero. If the valve is closed when the throttle is off idle, then the PAIR system as no effect while the bike is under power, blocking the PAIR will make no difference since it's 'blocked' by the valve anyway

Hmm... My 2008 BMW (very much fuel injection) doesn't have any air injection while my 1997 BMW (also fuel injected) does have a air injection. Now why would that be? I didn't say it was a good or bad system. Actually, if it helps reduce emissions, I have no problem with that as long as it doesn't- A) Hurt gas mileage B) Hurt performance C) Cause undo wear on the engine D) Fail, causing A,B, or C The PAIR system doesn't cause A,B, or C. The reason I took mine off was because I was misinformed, much like you. I was told it had to be disabled because it would interfere with my Autotune because the added air would throw off the O2 sensor. Turns out, that's wrong. The statement below is not a guess, or a theory, it's fact. I've actually gotten out a multimeter and saw this with my own eyes, on my bike. The ECU only only operates the solenoid air valve when- 1. The throttle is closed. 2. The coolant temp is below 168-ish Unless those 2 items are true, the valve is closed, meaning that PAIR doesn't effect A,B, or C. Now, since mine is already disabled, I see no reason to re-enable the system because of 'D'. That being said I would not disable just for the sake of 'D'. So.... The question that started this all, was that even thou I had removed all the hoses, the solenoid valve, and plugged the ports on top of the valve covers and air box, it did not prevent 'D' from happening because one of the reed valves under the port on the valve cover failed causing an exhaust leak in between cylinders. Does this leak cause a big problem? Did the valve seat 'melt' because the PAIR was disabled stopping any air flow ever? Is the only true way to prevent failure removing the reed valve and blocking the ports?

That is the most misguided and false explanation of the functional workings of the PAIR system I've ever seen. If all that was needed is to add air to the exhaust, there would be much easier and cheaper ways of doing that. Please go back read this link, I beg you. http://www.autoshop101.com/forms/h65.pdf

I never said anything about 'tubes'. Air in the oil-circuit?!? I would really suggest you read through this - http://www.autoshop101.com/forms/h65.pdf

Dirt from where?

While there is a external valve with the 3 hoses hanging off the airbox, there are also 2 reed check valves in each valve cover, one for each cylinder. Those are the valves in question, not the external one. Side note The air provided by PAIR to the exhaust is there to provide oxygen in hopes of burning any left over hyrocarbons as the exhaust is leaving the cylinder. The purpose is to reduce hydrocarbon emission during warm-up. It also helps to get the CAT heated up faster, again to reduce hydrocarbon emissions.

So 4 years ago now, I had plugged my PAIR at the valve covers in order to install Autotune. Shortly after that, I bought block plates but just last weekend got around to installing them. I installed the rear plate, no big deal, but when I got to the front I noticed that one of the reed valves had been leaking. The reeds 'close' against a layer of rubber that's molded around the plate opening. It would seem at some point the rubber had gotten 'heated', and was no longer flat causing a leak. It would seem to me, the purpose of the reed valve is prevent exhaust from traveling between cylinders and/or back to the airbox. Because I had the valve cover port plugged, the exhaust couldn't get back to the airbox but I wonder what problems can come from a port being open between cylinders. Well, I guess since one valve seemed fine, I had flow one way only. Today, I rode it to work and I swear it's never ran smoother. I'm not sure if it's because I fixed the leak or if it was just a really good day for the engine. You know, every engine runs a little different depending on condiitons of the day. Thoughts?

My first 'speed switch' actually reversed the fan, but I found it didn't lower the temp any faster then 'fan off' above 25-30 mph since the fan blade design is maximized for one direction. I also found that if the fans running and you flop the polarity without a pause, it pisses the motor off for no real reason.

I found it makes a huge difference. I noticed in stop light traffic, if you get the fan to started and start in motion, the fan pretty much cancels natural airflow. By turning the fan off at speeds above 25=30 mph, the cooling system works much better. I made a module that uses a freq counter to trigger a relay to kill the fan once speed is above 25-30 mph. I also have found that running a little richer mixture in gears 1-4 goes a long way in keeping things cool. I also think a series reg helps also, less heat generated.

Actually, starting '06 Honda stopped using dual filament bulbs and used a flasher with regulator to light the bulbs for running light mode, the Ebay flashers won't work. There's a way around it that's pretty cool if you're still interested.

For those interested, I just added the latest version for my Autotune generated PCV, version 6.6.12.

The switch can be had on Ebay here- http://www.ebay.com/itm/Adjustable-Vacuum-switch-6-24-inHG-lockup-700r4-2004r-/290698102042?hash=item43aef5051a&vxp=mtr I took the vacuum off where the Evap used to be.

Hey DanY1, what did good 'ol Tighwad say? I'm thinking the same thing you are - work up a mod that doesn't involve hacking up the factory wiring. Hey coderighter (thanks for the BMC filter, BTW), even though my Speedohealer is only making an 8% correction for my stock setup, is it possible that the bike will behave better if I make the mod you've suggested? Even small gains in ridability at small throttle openings are welcome. I do annual starter valve syncs and have a PCIII+O2elims both of which have gone a long way to making the bike behave nicely. If doing this mod would help in even the slightest way, I'd do it. Maybe the ECU is happier all around with the stock signal inputs. I'd set the correction back to 0%. If it runs better, than rewire it. If it runs the same, put it back to 8% and don't worry about it. Jon

Yes, map-by-gear well work on any PCV. Whether it makes a difference or not depends on the setup. It seems that '06 and newer are map-by-gear from the factory and would have the most to gain. However, someone with a pre '06 might want to tune gears 1-4 for the smoothest performance, while gears 5-6 could be tuned for the best gas mileage.

1) Yes 2) No, I'll have to cal it on the bike. The PCV has instructions on how to do this. Yes map by gear works with or without Autotune. Jon