S4 idle issue

Terryphukwit · 19-07-2021, 06:23 AM

Hi, new on here but hoping your experience with these fine beasts will help me solve this problem. Bought the bike in Jan, has since had a full service including clearances and belts, this problem has always been there and nothing so far done has helped or made it worse. Run from cold is fine, starts on the button every time, once warm again no real problem but run into traffic and need to slow the temp rises into the 80s and I start loosing a cylinder around idle, I can keep it running by lifting the idle but not great and quite often it stalls. Now here's the thing, give it a few seconds and restart and it's as if nothing was wrong, idles fine but not for long and it starts dropping a cylinder again. If I run from cold without riding it warms right through to the fans come on at 104 without an issue at all.
Please let me know your thoughts, the hot weather has made it worse so need to get it fixed..Thanks.. Marc..

slob · 19-07-2021, 07:57 AM

S4 has stick coils (in the plug caps), the front one particularly is prone to issues due to its location directly in the path of debris/water from the front wheel. if you swap the coils can you make the problem switch cylinders.
CBR600RR uses the same Denso coils, that are considerably cheaper to buy than Ducati ones.

Also is your battery healthy? Your ECU won't like low voltage supply, which you might see under the conditions you describe, although I'd expect you'd see starting problems too.

alan s4 · 19-07-2021, 08:01 AM

It took me about 5 years to sort out my S4 Gremlins!

Is your tacho behaving itself? Does it jump around at all?

1st job I would suggest is to change the reg/rect to a MOSFET - lots of info on here - 5 minute job if you use the Triumph leads.

Darren69 · 19-07-2021, 08:15 AM

+1 for the coil stick. That was the issue with mine but it was the rear one and did not appear to suffer any visible corrosion issues, it would just stop working when it got to a certain temp. When it cooled down it worked again. A new one from Ducati was iirc around £150 but as Rob says they are a Nippon Denso part fitted to many jap sportbikes of that era.

jerry · 19-07-2021, 10:12 AM

TPS not PERFECTLY adusted can also make idle and slow speed running bad or cause stalling

Terryphukwit · 19-07-2021, 01:42 PM

Thanks for the input guys, iv ordered a coil pack, as you say they fit other bikes so a Kawasaki 600 it is.
Also not sure if relevant or not, when I first turn on the ignition I get a message in the speedo, "NA Int" I have no idea what this is??

Darkness · 19-07-2021, 01:51 PM

Quote:

Originally Posted by Terryphukwit

Thanks for the input guys, iv ordered a coil pack, as you say they fit other bikes so a Kawasaki 600 it is.
Also not sure if relevant or not, when I first turn on the ignition I get a message in the speedo, "NA Int" I have no idea what this is??

The message is ‘MA Int’ and means the bike thinks it needs a service (Maintenance).

To get rid of it, press and hold the left button. Turn the bike on. Keep button pressed while the speedo/tach needles go up/down, and then turn the bike off. Now let go of the button. Now you should be all set.

Terryphukwit · 19-07-2021, 03:09 PM

Quote:

Originally Posted by Darkness

The message is ‘MA Int’ and means the bike thinks it needs a service (Maintenance).

To get rid of it, press and hold the left button. Turn the bike on. Keep button pressed while the speedo/tach needles go up/down, and then turn the bike off. Now let go of the button. Now you should be all set.

Genius, thanks

Terryphukwit · 22-07-2021, 05:48 AM

Quote:

Originally Posted by jerry

TPS not PERFECTLY adusted can also make idle and slow speed running bad or cause stalling

Hi Jerry
New coil pack did not fix it so I'm now looking at the TPS, I'm cool with the adjustment of it and have read through another thread but there were no readings given, would you know what output voltage it should be set at I assume closed and fully open.
Marc..

Darren69 · 22-07-2021, 07:39 AM

150mV fully closed. The formula is Voltage (mV) = 150 + degrees X 105. i don't know how easy it would be to get a reading, but you can use diagnostic software to get the angle readings

Luddite · 22-07-2021, 09:19 AM

Useful info.

http://www.bikeboy.org/ducati4vthrottleb.html

Terryphukwit · 22-07-2021, 08:29 PM

Thanks, had a look on my bike today and the original locking paint is still in tact, 18 years and not yet adjusted, I don have the proper kit but do have a multimeter so will be probing around in the morning, I am assuming the 3 x wires are live feed, ground and the output, reading to be take between ground and output.

Luddite · 23-07-2021, 12:29 AM

Quote:

Originally Posted by Terryphukwit

I am assuming the 3 x wires are live feed, ground and the output, reading to be take between ground and output.

From Brad's website...
"Connect to the TPS by whichever method you are using to measure the TPS output voltage – back probing wires, Mathesis, DDS, etc. You need to go into the outer two wires if back probing."

Terryphukwit · 23-07-2021, 04:55 AM

Quote:

Originally Posted by Luddite

From Brad's website...
"Connect to the TPS by whichever method you are using to measure the TPS output voltage – back probing wires, Mathesis, DDS, etc. You need to go into the outer two wires if back probing."

Thanks for this...

Terryphukwit · 23-07-2021, 06:59 AM

Morning gents, had a look at this this morning, early as I have work today, looks like the readings are ok, with everything disconnected so th butterfly snaps home fully I'm getting 153mv and connect everything back up 447. The 447 is what it was set to before I wound the throttle stop out to take the fully closed reading, the guy in the video is saying it should be lower, 350 but ultimately sets to 450 to get the degrees correct. This is the bit that looses me, surely this is set to whatever the bike idles correctly at or am I missing something.

19-07-2021, 06:23 AM	#1
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	S4 idle issue Hi, new on here but hoping your experience with these fine beasts will help me solve this problem. Bought the bike in Jan, has since had a full service including clearances and belts, this problem has always been there and nothing so far done has helped or made it worse. Run from cold is fine, starts on the button every time, once warm again no real problem but run into traffic and need to slow the temp rises into the 80s and I start loosing a cylinder around idle, I can keep it running by lifting the idle but not great and quite often it stalls. Now here's the thing, give it a few seconds and restart and it's as if nothing was wrong, idles fine but not for long and it starts dropping a cylinder again. If I run from cold without riding it warms right through to the fans come on at 104 without an issue at all. Please let me know your thoughts, the hot weather has made it worse so need to get it fixed..Thanks.. Marc..

19-07-2021, 07:57 AM	#2
slob . Join Date: Jul 2003 Location: East London Bike: Multiple Monsters Posts: 9,712	S4 has stick coils (in the plug caps), the front one particularly is prone to issues due to its location directly in the path of debris/water from the front wheel. if you swap the coils can you make the problem switch cylinders. CBR600RR uses the same Denso coils, that are considerably cheaper to buy than Ducati ones. Also is your battery healthy? Your ECU won't like low voltage supply, which you might see under the conditions you describe, although I'd expect you'd see starting problems too. Last edited by slob; 19-07-2021 at 08:04 AM..

19-07-2021, 08:15 AM	#4
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	+1 for the coil stick. That was the issue with mine but it was the rear one and did not appear to suffer any visible corrosion issues, it would just stop working when it got to a certain temp. When it cooled down it worked again. A new one from Ducati was iirc around £150 but as Rob says they are a Nippon Denso part fitted to many jap sportbikes of that era. __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

19-07-2021, 10:12 AM	#5
jerry Old Git Join Date: May 2006 Location: Cricklade Bike: Multiple Monsters Posts: 2,822	TPS not PERFECTLY adusted can also make idle and slow speed running bad or cause stalling __________________ MONSTERMAN

22-07-2021, 07:39 AM	#10
Darren69 Transmaniacon MOC Join Date: Sep 2013 Location: Sutton In Ashfield Bike: Multiple Monsters Posts: 6,023	150mV fully closed. The formula is Voltage (mV) = 150 + degrees X 105. i don't know how easy it would be to get a reading, but you can use diagnostic software to get the angle readings __________________ Roast Beef Monster! Termignoni and Bucci - Italian for pipe and slippers! S4 Fogarty, S4R 07T, 748, Series 1 Mirage

19-07-2021, 08:01 AM	#3
alan s4 Registered User Join Date: Sep 2013 Location: Glasgow Bike: S4 challenge Posts: 447	It took me about 5 years to sort out my S4 Gremlins! Is your tacho behaving itself? Does it jump around at all? 1st job I would suggest is to change the reg/rect to a MOSFET - lots of info on here - 5 minute job if you use the Triumph leads.

19-07-2021, 01:42 PM	#6
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	Thanks for the input guys, iv ordered a coil pack, as you say they fit other bikes so a Kawasaki 600 it is. Also not sure if relevant or not, when I first turn on the ignition I get a message in the speedo, "NA Int" I have no idea what this is??

22-07-2021, 09:19 AM	#11
Luddite Registered User Join Date: Aug 2011 Location: Southampton Bike: M1100evo Posts: 2,465	Useful info. http://www.bikeboy.org/ducati4vthrottleb.html

22-07-2021, 08:29 PM	#12
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	Thanks, had a look on my bike today and the original locking paint is still in tact, 18 years and not yet adjusted, I don have the proper kit but do have a multimeter so will be probing around in the morning, I am assuming the 3 x wires are live feed, ground and the output, reading to be take between ground and output.

23-07-2021, 06:59 AM	#15
Terryphukwit Registered User Join Date: Jul 2021 Location: Canterbury Bike: S4 Posts: 75	Morning gents, had a look at this this morning, early as I have work today, looks like the readings are ok, with everything disconnected so th butterfly snaps home fully I'm getting 153mv and connect everything back up 447. The 447 is what it was set to before I wound the throttle stop out to take the fully closed reading, the guy in the video is saying it should be lower, 350 but ultimately sets to 450 to get the degrees correct. This is the bit that looses me, surely this is set to whatever the bike idles correctly at or am I missing something.