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Discussion Starter · #1 ·
Another 'starting problem' thread: For the past few weeks my '02 Sprint RS takes several seconds to start after sitting for a few days. Once started, it runs a little rough before finally settling into an idle. After that it runs fine, and it will start fine after a short break. But give it a day of rest and the starting issue is there again. I've checked the spark plugs, air filter, hoses to the air box. I'm thinking it could be a throttle body sync issue, but the fact that it runs fine once it up and going has me scratching my head. What are your thoughts?
Thx!
 

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I've been experiencing that, too.
Use it every day or when ithe hot and no problem.
Summer gas forumla?
 

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Discussion Starter · #3 ·
I've been experiencing that, too.
Use it every day or when ithe hot and no problem.
Summer gas forumla?
Well I wasn't expecting that from you, Steve. I count on you to solve my bike's problems. :p
I pulled out my DIY manometer to see if TBS will help ... though the tubing has been stained by the fluid I used for it, making it difficult to see. I'll give it a try anyway.
Do you think the fuel may have something to do with it?
 

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Sorry I wasn't of more help, most of mine have always acted like that.
I think they just like to be used a lot.
 

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Discussion Starter · #6 ·
How long since you've done a valve adjustment/check? Cold start issues are often related to tight valves. A happy motor is a tappy motor.
I checked them about 5,000 miles ago (? guessing) - they were good, with one being so slightly tight that I didn't do anything about it. It was starting fine not long ago (less than a 1000 miles?). It's been several tanks of gas so I don't think that's the issue. Fuel filter? I have to look it up but I think I replaced it ~3 yrs ago.
 

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Discussion Starter · #8 ·
My understanding it's by design the engine turns over 3 full revolutions before firing when COLD thus allowing oil to all the important places.
This is more than just few turnovers ... and it's a recent development (I've had the bike ~6 yrs).
 

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I second Tiger about the valves.
Is the starter rotation speed fast enough?

Could you post a video?
 

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Fuel lines ok? I've had other bikes that loose pressure in the lines when parked up for a bit, so when they first run there's air in there. Within a few secs that works through & it's all smooth again.
 

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Yeah but the bike should normally prime the pump at turn key.

So one test than can be conducted is turn the key on and off a few times allowing for priming time (~2 sec - you hear it).
Then start up.
 

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Discussion Starter · #12 ·
I checked the valves yesterday - all within spec. Vacuum hoses are in good condition (new a couple of years ago). I have those fan-cooled LED lights installed ... the fans make just enough noise that they're what I hear first. :)
 
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Yeah but the bike should normally prime the pump at turn key.

So one test than can be conducted is turn the key on and off a few times allowing for priming time (~2 sec - you hear it).
Then start up.
It was another FI bike I'd seen the issue on & the priming cycle didn't seem to purge it.
 

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Every bike type has its own symptom, mainly because the ECU algorithms are dirrerent, so the decisions taken by the ECU are not the same.

One example: on the 1050, there is no cam sensor. So the manifold pressure sensor coupled w/ the crank sensor are giving the information about the cam shaft position in order to inject at the right stroke in order to start the bike. And the starting algo is differrent before and after 2007.
 

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My Sprint 1050 starts much easier than the Daytona 955i.
Both have been custom mapped with no O2 sensor, but it was always that way.
 

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Discussion Starter · #16 ·
@fredsprint The thing with my bike is that this starting issue is a recent development. It may have happened in the past, though ... I'm thinking a throttle body sync is the logical next step. I vaguely recall that helping last time. I should keep a record of these issues ... could be useful next time.
 

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Damp getting into the ignition coil caps ? Dries out once thoroughly warmed through...gets in again after sitting for a while?
 

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Discussion Starter · #19 ·
Thanks for the suggestion, @fredsprint.
This starting delay may seem normal to you, but it's a recent thing on this bike. And I wouldn't be this concerned if I wasn't planning a multi-day ride for next week where I'll end up being potentially a thousand miles from home and tools. Maybe you can also notice the uneven running until it finally settles in.

 

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Fairly typical characteristic of Triumph triples after a few years. Usually caused by injector bleed down and the fuel system not holding pressure for more than 24 hours. It can also be the valves have tightened up (lost most or all of their clearances) but you say you checked and they're okay so my money's on it's taking more than the usual number of cranks to build up fuel rail pressure.
 
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