S4 idle issue - Page 2

Darren69 · 23-07-2021, 07:13 AM

If you look back at the formula I posted each degree of the butterfly increases by 105mV and I think it is being set to around 2.6 degrees, which is 423mV so it's in the ballpark.

Luddite · 23-07-2021, 09:39 AM

If you read through Brad's instructions on his webpage it shows that the recommended setting for the S4 is 339mV at 1.8⁰ with final tickover determined usings the air bleeds.

Darren69 · 23-07-2021, 09:47 AM

Remember also that this is a non-linear TPS so the linear part is just up to 30deg for the 105mV formula.

Terryphukwit · 23-07-2021, 10:49 AM

Quote:

Originally Posted by Luddite

If you read through Brad's instructions on his webpage it shows that the recommended setting for the S4 is 339mV at 1.8⁰ with final tickover determined usings the air bleeds.

That now makes sense.. Thanks. .

Darren69 · 23-07-2021, 11:09 AM

Remember on those the TPS is Non-linear so the rule only works up to 30 deg IIRC.

Terryphukwit · 23-07-2021, 10:30 PM

Hi and thanks for all your help on this so far, I am hoping you guys are the patient type as we still have a way to go.
With confidence that the tps is pretty close I started reassembling the linkage and noticed the butterfly on the vertical cylinder was open further than the horizontal, I don't have vacumn guages so set the front using a wire guage and then set the rear to that, this was nearly a full turn on the linkage. then reset the idle position back to 400mv so spliting the difference between what it should be and what it was..strangely this lifted the idle slightly, I thought it would drop?, I set both air screws at 1 X turn out and headed out for a test ride with a long flat screwdriver in my jacket.
I would say this was smoother running at least at first, then got stuck in traffic and as usual it got bored with idling, instead of appearing to loose a cylinder as it did before it cut out completely, I think the vertical cylinder with the butterfly open was keeping it running before
and making it sound like it was missing on one cylinder. Spent some time trying to improve things with the air screws but no good, it stalls, you restart, it runs nicely for a short while then gets bored, starts running flat and uneven and stalls..
Not sure where to go from here, strange it runs ok after the restart, as if it resets but I am not turning off the ignition and not leaving it any time to cool.
I am also looking for a diagnostics tool if a cost affective one exists, I am wondering if the temp sensor that sends reading to the ecu is the same as for the guage and fans, I have seen this cause chaos before, worth a check.
Also not sure on my ECU, I have a feeling this is for termignoni pipes, I have Arrow with standard 2/1/2 headers, again could be an issue..

Again thanks for all your feedback, most appreciated.

Darren69 · 24-07-2021, 06:55 AM

The temp sensor on the front cylinder is for the display only. The one on the rear cylinder is for the ECU. I'm not sure what those codes on the ECU mean, they are not Ducati ones and appear to have been stuck over the Ducati ones. Probably means it has been remapped at some time, maybe someone will recognise them or if you Google them?

jerry · 25-07-2021, 08:52 AM

TPS has to be set absolutely perfect on S4 at 152mv or it will stall easy and run crap at low speed also battery and charging system must be in good order

Darren69 · 25-07-2021, 11:35 AM

I agree, but I think you can pretty much rule out the TPS now and look elsewhere since the issue appears to be temperature related. Maybe ECU or something in the ignition still?

Terryphukwit · 25-07-2021, 11:47 AM

I'm having another look this afternoon, I'm finding the ECU part numbers coming up for US models, my bike is a Japanese import so maybe this is why, I'm going to refit the standard exhaust as I got these with the bike, check all wiring on the engine and ECU, I would like to rule out the temp sensor that feeds back to the ECU if there is a way I can do this with a meter?? Otherwise I have found some ECUs on Ebay being sold in Italy by a legit looking seller, they are for bikes fitted with race cans as the only mod or for full race exhaust and open filter, they are also for bikes with kmh speedo which works, could go for one of these..

Mr Gazza · 25-07-2021, 12:47 PM

I think if you have reached an impasse with what you know and can test yourself, I would roll it into a trusted dealer or independent to get their informed opinion based on their huge experience and resource. It would certainly be money better spent than on introducing other components of unknown provenance.. In my opinion.

They might even be able to read a fault code and put their finger on it straight away?

Darren69 · 25-07-2021, 01:30 PM

I'd be inclined to agree with Gary. You could try swapping over the temp sensors and coil sticks to see if the problem moves but other than that I think I would throw in the towel at that point. Is it an '01 or '>02 bike?

Terryphukwit · 01-08-2021, 04:55 PM

Hi, not being very good at throwing towels anywhere I have pressed on a bit, reasonably confident with mt TPS and have cross checked temp sensor readings so read further though the forums, from what I read these bikes run very lean to combat emission restrictions, chatting with a guy on another forum who is working on adding a thermistor in series with the air temp sensor to trick the ECU into thinking the air is cooler so richening the mix a tad, have added a small resistor as that as al I had and has worked a treat, no stalling and much smoother at low revs, no really sure if it is the best value resistor for the job but this has proven to me that the issue is more than likely in the tune and not an actual fault.
So after advice again, would you get the ECU flashed or fit a PC. Thanks guys..

slob · 01-08-2021, 05:27 PM

ECU flash every time, the PC is just adding complexity and another point of failure, assuming you can access the ECU directly.
… and check you plugs if you’ve tricked the ECU by messing with the sensor outputs!

Terryphukwit · 01-08-2021, 09:08 PM

I plan to pull the plugs tomorrow, I have done around 100 miles so they should show some colour, they are iridium so not much of them, las time I looked at them they had done about 300 miles from new and they had no colour to them at all..
So I have no experience with having ECUs flashes, I understand this is the reprogramming of it, where is this done and is it then fine tuned on a dyno or is it just a suitable programme for the bike and that's it.
Thanks.....

23-07-2021, 07:13 AM	#16
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	If you look back at the formula I posted each degree of the butterfly increases by 105mV and I think it is being set to around 2.6 degrees, which is 423mV so it's in the ballpark. __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

23-07-2021, 09:47 AM	#18
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	Remember also that this is a non-linear TPS so the linear part is just up to 30deg for the 105mV formula. __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

23-07-2021, 11:09 AM	#20
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	Remember on those the TPS is Non-linear so the rule only works up to 30 deg IIRC. __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

23-07-2021, 10:30 PM	#21
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	Hi and thanks for all your help on this so far, I am hoping you guys are the patient type as we still have a way to go. With confidence that the tps is pretty close I started reassembling the linkage and noticed the butterfly on the vertical cylinder was open further than the horizontal, I don't have vacumn guages so set the front using a wire guage and then set the rear to that, this was nearly a full turn on the linkage. then reset the idle position back to 400mv so spliting the difference between what it should be and what it was..strangely this lifted the idle slightly, I thought it would drop?, I set both air screws at 1 X turn out and headed out for a test ride with a long flat screwdriver in my jacket. I would say this was smoother running at least at first, then got stuck in traffic and as usual it got bored with idling, instead of appearing to loose a cylinder as it did before it cut out completely, I think the vertical cylinder with the butterfly open was keeping it running before and making it sound like it was missing on one cylinder. Spent some time trying to improve things with the air screws but no good, it stalls, you restart, it runs nicely for a short while then gets bored, starts running flat and uneven and stalls.. Not sure where to go from here, strange it runs ok after the restart, as if it resets but I am not turning off the ignition and not leaving it any time to cool. I am also looking for a diagnostics tool if a cost affective one exists, I am wondering if the temp sensor that sends reading to the ecu is the same as for the guage and fans, I have seen this cause chaos before, worth a check. Also not sure on my ECU, I have a feeling this is for termignoni pipes, I have Arrow with standard 2/1/2 headers, again could be an issue.. Again thanks for all your feedback, most appreciated. Last edited by Terryphukwit; 23-07-2021 at 10:32 PM..

24-07-2021, 06:55 AM	#22
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	The temp sensor on the front cylinder is for the display only. The one on the rear cylinder is for the ECU. I'm not sure what those codes on the ECU mean, they are not Ducati ones and appear to have been stuck over the Ducati ones. Probably means it has been remapped at some time, maybe someone will recognise them or if you Google them? __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

23-07-2021, 09:39 AM	#17
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	If you read through Brad's instructions on his webpage it shows that the recommended setting for the S4 is 339mV at 1.8⁰ with final tickover determined usings the air bleeds.

25-07-2021, 08:52 AM	#23
jerry Old Git Join Date: May 2006 Location: Cricklade Bike: Multiple Monsters Posts: 2,822	TPS has to be set absolutely perfect on S4 at 152mv or it will stall easy and run crap at low speed also battery and charging system must be in good order __________________ MONSTERMAN

25-07-2021, 11:35 AM	#24
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	I agree, but I think you can pretty much rule out the TPS now and look elsewhere since the issue appears to be temperature related. Maybe ECU or something in the ignition still? __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

25-07-2021, 11:47 AM	#25
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	I'm having another look this afternoon, I'm finding the ECU part numbers coming up for US models, my bike is a Japanese import so maybe this is why, I'm going to refit the standard exhaust as I got these with the bike, check all wiring on the engine and ECU, I would like to rule out the temp sensor that feeds back to the ECU if there is a way I can do this with a meter?? Otherwise I have found some ECUs on Ebay being sold in Italy by a legit looking seller, they are for bikes fitted with race cans as the only mod or for full race exhaust and open filter, they are also for bikes with kmh speedo which works, could go for one of these..

25-07-2021, 12:47 PM	#26
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,816	I think if you have reached an impasse with what you know and can test yourself, I would roll it into a trusted dealer or independent to get their informed opinion based on their huge experience and resource. It would certainly be money better spent than on introducing other components of unknown provenance.. In my opinion. They might even be able to read a fault code and put their finger on it straight away? __________________

25-07-2021, 01:30 PM	#27
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	I'd be inclined to agree with Gary. You could try swapping over the temp sensors and coil sticks to see if the problem moves but other than that I think I would throw in the towel at that point. Is it an '01 or '>02 bike? __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

01-08-2021, 04:55 PM	#28
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	Hi, not being very good at throwing towels anywhere I have pressed on a bit, reasonably confident with mt TPS and have cross checked temp sensor readings so read further though the forums, from what I read these bikes run very lean to combat emission restrictions, chatting with a guy on another forum who is working on adding a thermistor in series with the air temp sensor to trick the ECU into thinking the air is cooler so richening the mix a tad, have added a small resistor as that as al I had and has worked a treat, no stalling and much smoother at low revs, no really sure if it is the best value resistor for the job but this has proven to me that the issue is more than likely in the tune and not an actual fault. So after advice again, would you get the ECU flashed or fit a PC. Thanks guys..

01-08-2021, 05:27 PM	#29
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,712	ECU flash every time, the PC is just adding complexity and another point of failure, assuming you can access the ECU directly. … and check you plugs if you’ve tricked the ECU by messing with the sensor outputs! Last edited by slob; 01-08-2021 at 05:32 PM..

01-08-2021, 09:08 PM	#30
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	I plan to pull the plugs tomorrow, I have done around 100 miles so they should show some colour, they are iridium so not much of them, las time I looked at them they had done about 300 miles from new and they had no colour to them at all.. So I have no experience with having ECUs flashes, I understand this is the reprogramming of it, where is this done and is it then fine tuned on a dyno or is it just a suitable programme for the bike and that's it. Thanks.....