FI light comes on after approx 20 miles

[yorkie_chris]

Depends, it only uses the O2 sensor for closed loop control when it's at cruise and needs that fine control over the mixture. AFAIK at varying speeds it reverts back to open-loop control so it doesn't mess about waiting for a steady O2 reading.

So it could be heat, or it could just put the light on when it wants to know what the O2 sensor has to say and can't find it.

[ophic]

Easy enough to test surely - ride with resistor, ride without resistor (if thats possible and the resistor isn't just there to fool some kind of start-up self-test) - compare results.

What YC says sounds very likely- i wouldn't expect the engine to getting that hot on a steady motorway cruise. Plenty of aircooling for the engine and radiator. The resistor might even have burnt out and is doing nothing so get a test meter across it and see what's what.

Originally Posted by yorkie_chris

Depends, it only uses the O2 sensor for closed loop control when it's at cruise and needs that fine control over the mixture. AFAIK at varying speeds it reverts back to open-loop control so it doesn't mess about waiting for a steady O2 reading.

So it could be heat, or it could just put the light on when it wants to know what the O2 sensor has to say and can't find it.

That makes sence YC.
What in your opinion is the best solution?
I suppose i could have a hole put in the system and re attach the lambda sensor?

Originally Posted by ophic

Easy enough to test surely - ride with resistor, ride without resistor (if thats possible and the resistor isn't just there to fool some kind of start-up self-test) - compare results.

What YC says sounds very likely- i wouldn't expect the engine to getting that hot on a steady motorway cruise. Plenty of aircooling for the engine and radiator. The resistor might even have burnt out and is doing nothing so get a test meter across it and see what's what.

I am pretty sure if i take resitor out the FI lights imideately - i will test it when i get chance.
I agree, YC makes good sence.

[yorkie_chris]

Originally Posted by stevebetts

What in your opinion is the best solution?

Get a bike with carbs on.
Or a TLS that doesn't have a lambda sensor

A resistor isn't generally good, what is it telling the ECU at cruise? Lean/rich? Certainly not conducive to proper control.

First I'd look at where you got the advice to use a resistor, how do they avoid this issue?
Can a reflash of the ECU tell it to use fully open-loop control?
Can you fit an early ECU that doesn't have the pesky sensor?

Then look at welding a boss into the pipe.

[ophic]

Originally Posted by yorkie_chris

A resistor isn't generally good, what is it telling the ECU at cruise? Lean/rich? Certainly not conducive to proper control.

No worse than bikes that don't have them. Carbed bikes have been managing without for years. Afaik pointy 650s don't have them either.

[yorkie_chris]

Originally Posted by ophic

No worse than bikes that don't have them. Carbed bikes have been managing without for years. Afaik pointy 650s don't have them either.

Yes I am aware of that.

However the ECUs of bikes not so equipped are not expecting a signal, and not trying to interpret a fixed resistance as something that it is not.

Originally Posted by yorkie_chris

A resistor isn't generally good, what is it telling the ECU at cruise? Lean/rich? Certainly not conducive to proper control.

First I'd look at where you got the advice to use a resistor, how do they avoid this issue?
Can a reflash of the ECU tell it to use fully open-loop control?
Can you fit an early ECU that doesn't have the pesky sensor?

Then look at welding a boss into the pipe.

The bike came with the exhaust system fitted and therefore the O2 disconnected.
I notice when you buy a PCIII it comes with basically the same thing.
I dont know how that deals with it.
I dont know if its possible to tell the ECU to use open loop control.
I will have to do some digging.

[yorkie_chris]

Yeah find out, it might be possible to get it on the yoshi box and flash the ECU.

Since you've got a full system, a remap wouldn't hurt anyway...

Originally Posted by yorkie_chris

Yeah find out, it might be possible to get it on the yoshi box and flash the ECU.

Since you've got a full system, a remap wouldn't hurt anyway...

been in touch with Dynojet today as they use the very same O2 sensor eliminator.
They were very helpfull.
They have the same issue - the trick is to remove cable 17 from the ECU (this is year dependant) to stop getting the FI warning.
They sent me the instructions showing this. If anyone wants a copy let me know and i will send it.