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Discussion Starter #1
Hi All,

I am new to the Forum and to Triumphs motorcycles. I recently purchased a 1999 Triumpt ST Sprint, 25000klms appox. I ride to work every day and for the last few months as not missed a beat. This weekend I gave it a wash, took it for a quick ride up the road and then parked it in the garage. This I have done every weekend since I purchased it.

But......This morning I started the bike, idling ok...half way out the garage it stalled. It would not start again, turned over ok but would not fire. I left it for a few minutes bad tried again, this time it fired but idling very rough and stalled. I started it again and this time kept the revs up high and it continued to run but very rough, let go of the throttle and stalled again. Tried this several times with the same result.

My knowledge is somewhat limited si I would appreciate it if someone could point me in the right direction on what might be causing the problem.

Is it possible that washing the bike has caused a water problem, even though I have done this every weekend, or is it possible it is something more sinister.


Thanks in Advance.
 

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Discussion Starter #3
After washing, common problem is water in the plug holes.
Need to pull the coils and dry them out.

Thanks for the quick reply. Can I ask a silly question, I do not have a workshop manual yet. Are the coils under the tank.?

Regards.
 

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Throttle on starting

I'll bet that you twisted the throttle when you started it???
If you did, don't touch it. Whatever position the throttle was in when the bike started that's where it thinks idle is viz the throttle position censor. When the throttle goes below that point it will die.
Just restart with your pinky on the starter button and NO twisting the throttle. It should be Ok.

Don
 

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Don't think this is correct.
While I agree these Triumph FI Triples do not like gas when starting, the explanation above is not valid.
According to my dealer it is. One mussent touch the throttle on a 99-04 955. I'll take my dealer's and his chief mechanic's word on things as they've never been wrong plus seeing is believing as I've seen this before with others.

I say again, you jaz the throttle during the start sequence and it doesn't know where idle is and a bike exhibits exactly the symptoms that the OP listed.
With water in the tube the engine will run after a fashion and idle. This I know because we do get a bit of rain here in Oregon and I've had this happen.
 

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.... Whatever position the throttle was in when the bike started that's where it thinks idle is viz the throttle position censor. ...
According to my dealer it is. ...
I say again, you jaz the throttle during the start sequence and it doesn't know where idle is....
I said 'think' being respectful - sorry D, this is just nonsense.
There is no FI system in the world that works like that.

What is actually happening in those conditions to make it run poorly (when the throttle is opened) is that the TPS tells the ECM to look at a point in the fuel map that is consistent with that throttle opening and apply the corresponding amount of fuel for that position.
The result is too much fuel and a rich/flooded condition that will cause the bike not to idle correctly (if indeed it is able to start like that). The fuel map has no temperature compensation (although there is provision in the ECM to have one if you use Tuneboy - all those cells in the OEM map are 'zero' on the Triumph map however)
i.e. there is no fueling compensation for a cold motor, so it does not like to take throttle - this can be further exacerbated depending on the exhaust that is installed. The only thing that IS adjusted for a cold motor is the idle speed is raised.
The suggestion that the TPS is offset by the amount it sees when the bike is started is just not the case.
The TPS position is reported to the ECM - it is generated by a simple potentiometer that gives a fixed output voltage directly corresponding to its relative position to 'closed'. That voltage will always be the same for any given throttle position, whether bike is idle or running, hot or cold.
What you are suggesting is that the ECM somehow takes that open throttle position and applies a recalibration (offset) to it 'on the fly' to say that is a new 'zero position. If it were sophisticated enough to do that, it would require to know the difference between running & idle conditions - what would stop it trying to 're-calibrate' that zero point at any point during its operation, but only at the point of ignition?? :confused:
The biggest question of all would be - why would it ever REQUIRE such a feature to incorporated in the algorithms? There is no reason to have such a 'feature' that can serve no positive benefit.
Sorry, just not buying your chief mechanic's 'theory'

But will it run rough/fail to start if throttle applied? Sure! For reasons stated above.

Reason I suspected water is because the owner has had the bike for several months without problems starting (apprently) and only experienced this immediately after washing. Being in the rain & potentially being deluged during washing not quite the same thing. It is odd that it ran fine immediately after washing though and probelm did not manifest itself till next day.
 

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Now this appears to be an interesting thread!

Wait a bit while I go grab some popcorn!

One question, and this isn't bait...

If the ECM 'spots' the TPS at it's zero position (fully closed) when it wakes up, what happens if the throttle is not fully closed (that is, being held open)? Would the voltage sent when the throttle is released be below the threshold the ECM is looking for?

Another feature of the earlier bike ECM is that it will run rich when it detects a throttle setting vs. engine speed/vacuum condition that indicates engine braking. I was told this by my highly competent mechanic, when I asked him about following a buddy (on a '99 Speed Triple) around the Dragon, asking why his bike got real 'gassy' on the downhills.

Lessee... Party Time or good ol' Orville...
 

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If you hold open the throttle after starting to increase revs to warm the bike up, after a certain period, the idle stepper drives off way downwards, and the exhaust gets red hot. Never did figure why this did so much damage ... maybe to do with the O2 sensor, is it only active at idle ?

I did this once. Warmed it for several minutes just off throttle. When I let go of the throttle, the Bike stalled instantly. Worse, one of the plastic fan blades on the radiator had melted, the blade nearest the centre exhaust, and the lower fairing had a egg sized bubble in it from the exhaust through the heat shield. Must have fooled the ECU into thinking the held throttle position was the new idle ....

Best if no one else tries this !
 

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I am going with water in the holes. The fact that it would turn over but not catch right after a wash leads to that.

maybe our new friend should post an update.
 

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If you hold open the throttle after starting to increase revs to warm the bike up, after a certain period, the idle stepper drives off way downwards, and the exhaust gets red hot. Never did figure why this did so much damage ... maybe to do with the O2 sensor, is it only active at idle ?

I did this once. Warmed it for several minutes just off throttle. When I let go of the throttle, the Bike stalled instantly. Worse, one of the plastic fan blades on the radiator had melted, the blade nearest the centre exhaust, and the lower fairing had a egg sized bubble in it from the exhaust through the heat shield. Must have fooled the ECU into thinking the held throttle position was the new idle ....

Best if no one else tries this !
Not being a smart arse, but why would you want to hold the throttle open just after a cold start anyway?

If everything is set up as it should you just start it put your helmut and gloves on and ride off don't you?

Or am I missing something in my warm cosy climate down here in a warm part of Ozz?

DaveM:cool:
 

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If you hold open the throttle after starting to increase revs to warm the bike up, after a certain period, the idle stepper drives off way downwards, and the exhaust gets red hot.

Best if no one else tries this !
I know folks that fast idle cars to warm them up faster. I am busy putting on my gear while the bike warms up, so have never been tempted to do this
BTW: I will drive my car (gingerly) before it is fully warm, but never the bike.
 

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Cold starts

I know folks that fast idle cars to warm them up faster. I am busy putting on my gear while the bike warms up, so have never been tempted to do this
BTW: I will drive my car (gingerly) before it is fully warm, but never the bike.
Listen,

It is not good to hold the throttle open at idle when cold, warm the engine up by riding and do not give the engine high revs until it is warmed up.

If you rev the engine out when cold don't blame anyone when it starts to burn oil later.

DaveM
 

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Good point Dave. I never do that to warm the Bike before I ride it off. It was last Winter, the Bike was in the Garage, and I wanted to run it to warm it through before putting it to sleep again. I just held the throttle to give me around 3000 RPM once the Bike was off cold to warm it up to the fan kicking in quicker. Something wierd happened as I said, and the Rad fan blade got melted and the fairing bubbled at the closest point underneath.

Moral is : Don't try to warm the engine up quicker by holding the revs. Apart from the longer term damage, you will melt something !:eek:
 
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