Odd behavior after service?

[Keith]

Last Wednesday I changed plugs, air filter, and installed J Red's PAIR valve kit. Bike was running fine.

Took a 200 mile ride through Yosemite Valley on Friday; bike ran great. Saturday, I rode a loop over the

Sierra Nevada mountains to the east side then back over to home. When I stopped at about the 8000 foot

elevation for a break, the bike would not idle; it died as soon as I pulled in the clutch at the stop. It has

never done that before. I turned up the idle with the adjuster and it ran fine again. I next stopped in

Sonora Pass at 10,000 feet, and it died again; wouldn't idle. I turned up the idle again, and it ran fine.

It is still running fine and idling correctly. I probably turned the adjuster four or five turns to get it to

idle at 1200 RPM.

I've been over those passes dozens of times and never had a problem with the way the bike ran,

so I'm pretty sure it didn't have anyting to do with the elevation; I'm wondering what else could

be causing it. Has anyone else who has put on J Red's PAIR valve kit experienced a problem like

this? Has anyone on the board encountered this sort of problem for any other reason? If so, what

was the cause and solution?

[XX4me]

Last Wednesday I changed plugs, air filter, and installed J Red's PAIR valve kit. Bike was running fine.

Took a 200 mile ride through Yosemite Valley on Friday; bike ran great. Saturday, I rode a loop over the

Sierra Nevada mountains to the east side then back over to home. When I stopped at about the 8000 foot

elevation for a break, the bike would not idle; it died as soon as I pulled in the clutch at the stop. It has

never done that before. I turned up the idle with the adjuster and it ran fine again. I next stopped in

Sonora Pass at 10,000 feet, and it died again; wouldn't idle. I turned up the idle again, and it ran fine.

It is still running fine and idling correctly. I probably turned the adjuster four or five turns to get it to

idle at 1200 RPM.

I've been over those passes dozens of times and never had a problem with the way the bike ran,

so I'm pretty sure it didn't have anyting to do with the elevation; I'm wondering what else could

be causing it. Has anyone else who has put on J Red's PAIR valve kit experienced a problem like

this? Has anyone on the board encountered this sort of problem for any other reason? If so, what

was the cause and solution?

The PAIR system and the Starter Valve, which is what the idle speed adjustment screw on FI bikes is connected to, are not connected in anyway. The PAIR system consists of a soleniod that either opens or closes at the direction of the ECU to allow air into the exhaust. Shouldn't have any effects at all on the idle mixture.

I'm afraid it's a case of "Post Hoc Ergo Propter Hoc" after this therefore because of this.

Did you check all the vacuum lines.

[Keith]

The PAIR system and the Starter Valve, which is what the idle speed adjustment screw on FI bikes is connected to, are not connected in anyway. The PAIR system consists of a soleniod that either opens or closes at the direction of the ECU to allow air into the exhaust. Shouldn't have any effects at all on the idle mixture.

I'm afraid it's a case of "Post Hoc Ergo Propter Hoc" after this therefore because of this.

Did you check all the vacuum lines.

Yeah, it seemed to me that there couldn't possibly be any connection between the two, but since

the PAIR valve kit was the only thing I changed other than plugs and air filter, it is the only culprit

that I can think of. I have checked and no hoses are disconnected, so don't think it's a vacuum leak;

besides, wouldn't a vacuum leak more likely cause a fast idle rather than low?

Thanks for the reply.

[demon]

Whether the engine speeds up or slows down when there is a vacuum leak depends on the richness or leanness at idle. A rich idle will speed up when a leak occurs whereas a lean mixture at idle will slow down.

[azxx]

May have had a O2 sensor glitch, the pair valves let air in the exaust stream and that increases exaust gas temp. I don't have a FI XX but I know on my CBR1000F when I removed the emmissions (air injection system) the exaust ran cooler.

[XX4me]

May have had a O2 sensor glitch, the pair valves let air in the exaust stream and that increases exaust gas temp. I don't have a FI XX but I know on my CBR1000F when I removed the emmissions (air injection system) the exaust ran cooler.

I bet you're right about the O2 sensor, I just noticed it's a CA bike.

If you quit introducing air into the exhaust the O2 sensor will read that as a rich condition and promptly lean things up.

Keith are you running a Power Commander?

[Keith]

I bet you're right about the O2 sensor, I just noticed it's a CA bike.

If you quit introducing air into the exhaust the O2 sensor will read that as a rich condition and promptly lean things up.

Keith are you running a Power Commander?

Yes, it is a CA bike and I am running a Power Commander. I have not installed the O2 sensor bypass

that I purchased along with the PC, but could do so if that might be the problem here. I run a PC map

that does not include the O2 bypass.

[XX4me]

I bet if you put the bypass in it will quit acting funny.

This is interesting............

[Iceman_40]

I bet if you put the bypass in it will quit acting funny.

This is interesting............

+1

I bet it thinks your bike is running rich from not getting as much O2 across the sensor and the computer is leaning it out.

[Keith]

I bet it thinks your bike is running rich from not getting as much O2 across the sensor and the computer is leaning it out.

I guess I don't understand how the O2 sensor works, then. Shouldn't it be reading whatever it is

that's coming out of the exhaust port and causing the ECM to adjust accordingly? With or without

the PAIR valves, the exhaust gas mixture is what it is and the whole system should adjust the

air/fuel mixture to be correct; with the O2 sensor, it's a closed loop system, right? Can you

explain the mechanism by which the error is occuring? I sure would like to know how it works.

[Red J]

usually, the O2 sense system works under part throttle cruise. The sensor is not extremely accurate, so the ECU takes it from lean to rich and back again, cyclically. Closed loop system.

under decel, the O2 may be monitored, I don't know.

under wide open throttle, or even near it, the O2 will be disregarded, as it is not fast enough nor accurate enough to be reliable. Under these conditions, where the O2 is not consulted, the ECU relies on it's preprogrammed maps and the other sensors (manifold pressure, throttle position, RPM, coolant temp.) to feed the engine fuel and adjust spark advance. Open loop system.

that's basic. There are some other things that come into play, but that's the meat and potatoes of it.

The O2 eliminators remove the sensor from the ECU, and feed it a value. What exactly, I'm not sure.

[Red J]

I am sorry to hear this, by the way. I have not had anyone contact me with a similar issue.

I'm not saying it isn't responsible, because it sure would seem to be the case. I have had a few California customers, but no issues until yours.

J.

[Red J]

I bet it thinks your bike is running rich from not getting as much O2 across the sensor and the computer is leaning it out.

I guess I don't understand how the O2 sensor works, then. Shouldn't it be reading whatever it is

that's coming out of the exhaust port and causing the ECM to adjust accordingly? With or without

the PAIR valves, the exhaust gas mixture is what it is and the whole system should adjust the

air/fuel mixture to be correct; with the O2 sensor, it's a closed loop system, right? Can you

explain the mechanism by which the error is occuring? I sure would like to know how it works.

Does it idle faster before dying? Did it idle fine after the pair mod? Only after you rode was it a problem?

[Keith]

Does it idle faster before dying? Did it idle fine after the pair mod? Only after you rode was it a problem?

It did not idle faster before dying; the RPMs simply fell off to about 200 or 300 and then the engine died.

It did idle fine initially after the PAIR valve mod; I rode a short 125 mile ride the day after the mod and a

longer 230 mile ride the next day. It was the third day, when I was up in the high Sierra Nevada mountains

that the idle became an issue. I was guessing it was due to elevation, since I was up between 8000 and

10000 feet. However, the idle did not increase as I came down hill, which I have expected due to me having

cranked it up with the idle adjust screw; if it was elevation related, I would have expected to have to

adjust the idle back down when I got to lower elevations.

[Keith]

that's basic. There are some other things that come into play, but that's the meat and potatoes of it.

Thanks for the detailed description; I really appreciate it.

The O2 eliminators remove the sensor from the ECU, and feed it a value. What exactly, I'm not sure.

I'll try putting the eliminator in the system and see what happens. First I have to find where the unit

plugs into the harness; I hope it's easy to locate...

[Keith]

Just thought I'd give an update on this:

Today, I tore into the 'bird to see what I could find related to the idle problem. I checked all hoses, etc.

but found nothing amiss. The zip tie had come off the little cap J Red includes with the PAIR valve kit to

close off the hose connection to the air box, but the cap was still there and was tight; I put another zip

tie on it. So, no source for leaks that I could find.

Next step was to find the O2 sensor connector and install the eliminator from Power Commander. That

was easier said than done, but I did finally locate it under a protective plastic sleeve where a bunch of

wiring connects to the main harness. With the eliminator installed, I buttoned everything back up,

downloaded a PC map for bikes with the O2 eliminator installed, and fired her up. Once the engine

reached operating temperature, the idle was still about where I last set it, perhaps slightly higher;

I reset it to 1100. Next will be a test ride, but I can't do that until Wednesday.

I was hoping that the idle would be very high after the install of the O2 eliminator, because of my having

to set it high to keep the bike running, but that isn't the case. Maybe the ECU has made some permanent

change to its map to account for the rich condition it was getting from the O2 sensor. I don't know, but time

will tell, I guess.