Hot and cold starting...

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Nov 6, 2015
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A couple of weeks ago the bike started taking multiple attempts to start when warm - it would catch but not run on. Now it's showing the same reluctance when cold. I'm assuming it's a sensor problem with the ECU getting some duff information. Anyone experienced similar and solved it? Battery is fine, nothing has changed, it used to start first try hot or cold. I've taken it out for a good run once started to make sure it's not a case of sitting still to long.
 
Starts great when nobody's looking. Only takes multiple tries in front of a crowd. :roll:
 
I have yet to install my new head temp. sensor, but I am convinced it is the cause of my starting issues. Mine starts easily when the temperature is below 60° and the battery is at full charge. I do not have a problem after it's warmed up, though.
 
Thanks for the replies, my suspicion is the engine temp sensor. At work at the moment but will take a close look tonight. Is there a replacement part number for it? Can't be bothered to take it to the dealer if its simple enough to replace.
 
Thanks Richard, first post in the thread duh - feeling a bit embarrassed. :oops:
 
Shot home at lunchtime, pulled off the sensor plug tried starting the bike. No joy after a few stabs at the starter. Measured the resistance @ 2.9k ohms. Reconnected the plug and it started straight away. Left it idling for 5 - 10 minutes. Removed plug and re-measured resistance approx. 350 ohms so sensor good - although I found it difficult to get any reading on a few occasions which could either be an intermittent fault or just the tricky access. Anyway sprayed it with some electrical cleaner plugged it back in and again it started first crack. So at this stage putting it down to a poor electrical contact, but I may source a spare just in case. Hope it helps someone in the future.
 
BPHORSEGUY said:
I love a Happy ( and free ) ending!

Still looking for my happy ending. She started up on the first try around lunchtime when the ambient temperature was in the low 60s. She sat the rest of the day until 5 PM when the temperature had climbed to 69° ... that's when I had trouble. Four attempts, three with the battery jump starter. I can't decide if it's the battery or the sensor. But it drives me nuts!! :x
 
contours said:
BPHORSEGUY said:
I love a Happy ( and free ) ending!

Still looking for my happy ending. She started up on the first try around lunchtime when the ambient temperature was in the low 60s. She sat the rest of the day until 5 PM when the temperature had climbed to 69° ... that's when I had trouble. Four attempts, three with the battery jump starter. I can't decide if it's the battery or the sensor. But it drives me nuts!! :x

Rule of thumb, when Diagnostics are too expensive or just not available, start by replacing the cheapest suspect part in the system. I'm pretty sure the sensor is cheaper then the battery and quicker to replace, if it doesn't work at least you'll have a spare!
 
BPHORSEGUY said:
I'm pretty sure the sensor is cheaper then the battery and quicker to replace, if it doesn't work at least you'll have a spare!

Not quite so, Grasshopper. The genuine Bosch sensor I purchased cost more than a replacement battery. The big question is what "superior" battery should I buy and will that mysterious voltage drain ruin even the best battery? :?
 
contours said:
BPHORSEGUY said:
I'm pretty sure the sensor is cheaper then the battery and quicker to replace, if it doesn't work at least you'll have a spare!

Not quite so, Grasshopper. The genuine Bosch sensor I purchased cost more than a replacement battery. The big question is what "superior" battery should I buy and will that mysterious voltage drain ruin even the best battery? :?

You may want to look at the link I posted in sensors trial. The Bosch sensors at AutohausAZ were not expensive at all. They are listed as Bosch and then the had alternatives, not Asian.
 
contours said:
BPHORSEGUY said:
I love a Happy ( and free ) ending!

Still looking for my happy ending. She started up on the first try around lunchtime when the ambient temperature was in the low 60s. She sat the rest of the day until 5 PM when the temperature had climbed to 69° ... that's when I had trouble. Four attempts, three with the battery jump starter. I can't decide if it's the battery or the sensor. But it drives me nuts!! :x


Have you tested the existing sensor with a multimeter?
 
iwilson said:
Have you tested the existing sensor with a multimeter?

No, I haven't. Where do you place the electrodes? Maybe I can do it at my workplace where I've been keeping the bike.
 
BPHORSEGUY said:
contours said:
BPHORSEGUY said:
I love a Happy ( and free ) ending!

Still looking for my happy ending. She started up on the first try around lunchtime when the ambient temperature was in the low 60s. She sat the rest of the day until 5 PM when the temperature had climbed to 69° ... that's when I had trouble. Four attempts, three with the battery jump starter. I can't decide if it's the battery or the sensor. But it drives me nuts!! :x

Rule of thumb, when Diagnostics are too expensive or just not available, start by replacing the cheapest suspect part in the system. I'm pretty sure the sensor is cheaper then the battery and quicker to replace, if it doesn't work at least you'll have a spare!
Exactly the procedure I followed. Ended up by replacing the head temp sensor as almost last of the sensors and yes, this one was defective...
 
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