Poor staring when hot. 2011 efi Bonneville - Triumph Forum: Triumph Rat Motorcycle Forums
Air Cooled Twins Technical Talk Technical Talk for Hinckley Triumph Twins: Bonneville, Bobber, T100, Speedmaster, America, Thruxton, and Scrambler. Sponsored by: triumphtwinpower.com

 3Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 13 (permalink) Old 10-19-2019, 08:36 AM Thread Starter
Grand Prix 125
Main Motorcycle: Bonneville 2011
Member
 
Join Date: Apr 2017
Location: Blyth Northumberland UK
Posts: 37
Other Motorcycle: Le Velocette 1951
Poor staring when hot. 2011 efi Bonneville

Hi Folks

Recently the bike has failed to start when hot. Leave it for a cool down period and it's fine.

When running there is no indications of a problem.

Currently thinking coil breakdown.

Idea's please before I commit to purchasing a coil.

Whilst I sort this issue I am only stopping where there is a cafe that serves good coffee, well that's my excuse.

Philip
Blyth
Northumberland
England
Tornadof3 is offline  
Sponsored Links
Advertisement
 
post #2 of 13 (permalink) Old 10-19-2019, 09:14 AM
Site Supporter
Supernova
Main Motorcycle: 2009 Bonneville SE
Lifetime Premium
 
Forchetto's Avatar
 
Join Date: Jun 2009
Location: Asturias, Spain
Posts: 20,722
Other Motorcycle: Yamaha XV1100
Extra Motorcycle: Qingqi QM200GY-BA
Assuming you're using the same starting procedure as when it started fine, stuff like a closed throttle, a little "choke" when partly warm (as per owners manual), etc, the main suspect could be the old pick-up coil or CPS (crank position sensor).

These tend to give trouble when hot and detection is not easy, as it involves measuring its resistance and Sod's Law says that by the time you find the cunningly hidden connector, got your multimeter out, etc the thing has cooled down and measures correctly.

It ought to flag up a fault code and light the engine check light, but it often doesn't.


The ignition coil on EFI models is very durable and reliable and seldom gives trouble, by the way. I say this because a replacement costs 113 so changing it is not a decision to be taken lightly.

Last edited by Forchetto; 10-19-2019 at 09:19 AM.
Forchetto is offline  
post #3 of 13 (permalink) Old 10-19-2019, 11:12 AM
Moto Grand Prix
Main Motorcycle: 2010 Bonneville SE
Senior Member
 
Ripper's Avatar
 
Join Date: Mar 2010
Location: Staffordshire UK
Posts: 2,881
Quote:
Originally Posted by Forchetto View Post
Assuming you're using the same starting procedure as when it started fine, stuff like a closed throttle, a little "choke" when partly warm (as per owners manual), etc, the main suspect could be the old pick-up coil or CPS (crank position sensor).

These tend to give trouble when hot and detection is not easy, as it involves measuring its resistance and Sod's Law says that by the time you find the cunningly hidden connector, got your multimeter out, etc the thing has cooled down and measures correctly.
Fully agree. The way to test the CPS is remove it completely from the bike when cold, measure the coil resistance, then dump it into a jug of boiling water for a couple of minutes. Take another resistance reading and if there's a large difference between the two readings, the coil is most likely duff. The CPS is notorious for this specific problem.
To be fair, the cost of a new gasket, oil leakage (that's if you have no way of doing this with the bike lying on its side) and sheer pain in the backside to do, is prohibitive against just replacing the CPS to eliminate it. Compared to the rest of the ignition system the CPS is the cheapest item to replace, so its worth taking that gamble before you start looking at replacing ignition coils. Whilst removing the CPS I would also check the condition of its wiring and connector.
One other word of caution (or would it be a tip?) is the rubber grommet which the CPS wires run through, in the triangular engine case. This will undoubtedly seep engine oil after the job is done, unless you use silicone sealant (I use the tar-like roof/gutter sealant) to seal the rubber into the engine case.
Forchetto likes this.

Arrow 2-2, Snorkel/Baffle removed, DNA filter, TTP Tune#3, TEC piggy back gas shocks, 5.5" risers with drag bars, LED Lighting, Hazards, Oberon Footpegs, Burton Seat, D9 bracketry, Hands Free Keyless ignition.
Ripper is offline  
 
post #4 of 13 (permalink) Old 10-19-2019, 05:33 PM
Formula Extreme
Main Motorcycle: 2010t100 67 ttspecial rep
Senior Member
 
mike-tt special's Avatar
 
Join Date: Apr 2012
Location: N wales uk
Posts: 929
Other Motorcycle: 91 zxr750(805cc)
Garage
As you say that the bike runs fine once started even when it is hot i doubt it is the CPS...

As you say it starts fine when cold and it is just a hot starting issue my investigations would centre around the various temp sensors that feed data to the ECU.
Does the bike have pod air filters? And if so, where is the iat sensor positioned?
Is the barometric air pressure sensor clear and working
Is the oil temp sensor working?
Etc
mike-tt special is offline  
post #5 of 13 (permalink) Old 10-21-2019, 04:45 AM Thread Starter
Grand Prix 125
Main Motorcycle: Bonneville 2011
Member
 
Join Date: Apr 2017
Location: Blyth Northumberland UK
Posts: 37
Other Motorcycle: Le Velocette 1951
Good Morning Gentlemen

First. Thank you for your help, its greatfully received.

The bike started with the problem last week on a ride out, luckily at a cafe stop so it cooled down whilst we had our drinks.

The bike has no intake mods other than a new filter last week?

The air injection system was removed one year ago, a good mod.

Starting system, fully retard ignition, tickle carb, index finger on valve lifter oops wrong bike and showing my age. The bike starts normally without any help, not even choke. Its rare to need to put the choke on?

I will order a CPS tomorrow once the Triumph dealer is open, monday is a closed day.

Any suggestion on how to test other sensors. I am competent with a multi meter.

Philip
Tornadof3 is offline  
post #6 of 13 (permalink) Old 10-21-2019, 06:04 AM
World SuperBike
Main Motorcycle: 2008 Bonnie Black Special
 
PieMan's Avatar
 
Join Date: Feb 2007
Location: Bournemouth, England
Posts: 2,333
Quote:
Originally Posted by Tornadof3 View Post
The bike starts normally without any help, not even choke. Its rare to need to put the choke on?
That's your problem right there, you should need the fast idle (choke) from cold, if not then your mixture is far too rich.

On a correctly jetted (oops, wrong bike ) EFI Triumph twin you should need fast idle when cold for a couple of minutes and then when hot starting, just for a couple of seconds to ensure a good idle.

If your old filter was really dirty, the new filter would allow more air through to give a little leaner mixture.

Mike (UK)

08 Bonnie Black Special

https://www.triumphtwinpower.com
PieMan is offline  
post #7 of 13 (permalink) Old 10-21-2019, 03:36 PM Thread Starter
Grand Prix 125
Main Motorcycle: Bonneville 2011
Member
 
Join Date: Apr 2017
Location: Blyth Northumberland UK
Posts: 37
Other Motorcycle: Le Velocette 1951
Hi Pie Man

All noted. Starting from cold is not a problem, it was hot starting that was the issue.

No, the old filter was clean, it was time changed that's all

Thanks for the inputs.

Now struggling to find the route of the CPS cable.

Philip
Tornadof3 is offline  
post #8 of 13 (permalink) Old 10-21-2019, 04:37 PM
Site Supporter
Supernova
Main Motorcycle: 2009 Bonneville SE
Lifetime Premium
 
Forchetto's Avatar
 
Join Date: Jun 2009
Location: Asturias, Spain
Posts: 20,722
Other Motorcycle: Yamaha XV1100
Extra Motorcycle: Qingqi QM200GY-BA
Quote:
Originally Posted by Tornadof3 View Post
Now struggling to find the route of the CPS cable.

The connector is cunningly hidden between the top of the airbox and the frame. To get at it you might have to remove battery and ECU, loosen airbox fixing bolts and airfilter to throttle body clamps and pull the airbox down and back. I've extracted mine and tied it to the fusebox for easy access for fault-finding, like this:


Forchetto is offline  
post #9 of 13 (permalink) Old 10-21-2019, 10:20 PM
Grand Prix 500
Main Motorcycle: 2013 Bonneville T100
Senior Member
 
CapitalSon's Avatar
 
Join Date: May 2016
Location: Houston, TX
Posts: 113
Other Motorcycle: 1955 AJS 350 (ex)
Garage
Are you pulling out the "choke" to the first position EVERY time, hot or cold - that's what the manual says.

2013 T100 - Cranberry Red, New England White, Triumph QR Screen, Racetech Shocks-F, YSS Shocks-R, Biltwell Grips, Moto bars, RoxSpeed Risers, GIPro DS, MC/NightRiderz LED Tail/Head light, Scotolier, Michelin Anakee III's, TORs; No SAI, ECS, Baffle
CapitalSon is offline  
post #10 of 13 (permalink) Old 10-22-2019, 04:27 PM Thread Starter
Grand Prix 125
Main Motorcycle: Bonneville 2011
Member
 
Join Date: Apr 2017
Location: Blyth Northumberland UK
Posts: 37
Other Motorcycle: Le Velocette 1951
Hi Folk.

To all who have advised on the starting technique my thanks, but it's not that...

To Forchetto, my humble thanks. Your information has been invaluable. The plug for the cps was near where you said but was a real *******, they had wrapped the cable around a large loom and so I cut off the plug to take it out. No worries being an ex electrical engineer. New sensor should arrive wednesday and will re route as you suggested. The worst bit was that in assembly they had tie wrapped the cables together as the come up from beneath the gear box, that took twenty minutes of struggle to cut off. I will make a reply in a few days once the cps is fitted engine is running, hmmm hopefully.

Out of interest I would like to know if the temp sesnors etc can be tested?

God Bless Philip

Last edited by Tornadof3; 10-22-2019 at 04:30 PM.
Tornadof3 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options
All posts must adhere to Forum Rules

Register Now



In order to be able to post messages on the Triumph Forum: Triumph Rat Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter your valid email address, that can receive an automated confirmation message. Otherwise, you won't be able to gain full access.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome