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Posted

Yah, those are very different, and nothing like what I would predict, although for the most part we can see one cylinder certainly needs more fuel, but the change at higher throttles defies what I would predict.

I thought the differences would follow the RPMs more than the throttle position.

My TuneBoy is supposed to have that functionality, but I have not figured it out yet.

Thanks for posting that.

Motoguzznix did an interesting study in A:F ratio of each cylinder

Posted
Yah, those are very different

I'm not sure about that. If I understand that table right, they are an offset in the order of tenths of µs from the global map which will be in the order of thousands of µs. So the resulting net difference between cylinders is usually less than 2%. That is also what Cliff has experienced when trying dual sensors IIRC.

 

As far as I know the difference between unmatched injectors may be bigger than that.

Posted
What is "us"?

It should say µs but I'm lazy. Microseconds. I just edited my post for you ^_^

Posted

May be two injections per stroke? the first inject more fuel than first?

 

I had a poor idle if tps set 150mv. If you see the front cylinder table, idle inject 21us. I modified to 24

Now I have a perfect idle. I dont modified the rear cylinder fuel table.

Posted

If you modified the table from 21 to 24 I take it you went from 42 µs to 48 µs (the table says "2 µs per bit" in the heading). But I can't imagine how that could make a difference on a total of maybe 4,200 µs.

Posted
What would happen if you raised the TPS to 500 or 521mV and closed the air bypass screws enough to keep the proper idle?

What is the reason you chose 485mV?

If you go to a higher mV than 485, it seems like you might get rid of the occasional hiccup around 2800 RPM on light throttle, reduce valve recession, reduce engine vibration, extend engine life, and maybe lose 1 or 2 MPG.

 

Raising the TPS and closing the bypasses to maintain idle RPM would richen the mixture at idle and wider throttle openings up to the point where the bypass flow becomes insignificant compared to the total flow.

485 mv was merely one of the recommended numbers in the development of the TPS synch thread. I was happy to keep it there instead of higher numbers because of the improved fuel mileage.

What you say higher mv's makes sense. However, the effect is so seldom, and random, it behaves like a hiccup in the ECU's control algorithm. It's as if the firmware gets temporarily confused, or there is an intermittent connection to a sensor.

 

When I get a chance, I'll try what you suggest. However, it will take a lot of flawless performance before the cause/effect relationship is confirmed.

 

best, John

Posted
However, it will take a lot of flawless performance before the cause/effect relationship is confirmed.

No doubt. Changes in weather and random differences in gasoline quality can throw off subtle differences in engine behaviour.

Thanks for the comments :bier:

Posted
....the effect is so seldom, and random, it behaves like a hiccup in the ECU's control algorithm. It's as if the firmware gets temporarily confused....

 

I've seen this 'hiccup' reported before. I think it was the developer of tuneboy who spoke about it, but that was quite some time ago now, you know.

 

Hubert

Posted
I've seen this 'hiccup' reported before. I think it was the developer of tuneboy who spoke about it, but that was quite some time ago now, you know.

 

Hubert

 

Interesting. Since my bike is a leftover '04, it's possible that later debugging of the ECU program would not have been applied to my bike. If any of the service tech experts are monitoring this, I would like to hear from them on whether there has been a service note on this.

 

:huh2:

Posted
I've seen this 'hiccup' reported before. I think it was the developer of tuneboy who spoke about it, but that was quite some time ago now, you know.

 

Hubert

The Guzzis with 16M allegedly had a hiccup or miss bug. But the bug would nearly disappear when chipped to run richer.

 

“Computers aren't intelligent, they only think they are” --unknown

Posted
Interesting. Since my bike is a leftover '04, it's possible that later debugging of the ECU program would not have been applied to my bike. If any of the service tech experts are monitoring this, I would like to hear from them on whether there has been a service note on this.

 

:huh2:

Interesting question.

And if any tuneboy junkies out there have some maps to share, maybe we should start a file share...

Posted

I wouldn't be too surprised if you was the only one who uses this progie, David.

 

Hubert

Posted
I wouldn't be too surprised if you was the only one who uses this progie, David.

 

Hubert

This could be worth poll...

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