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Re: [ST] poor performance on second start



Quoting Jean Doublet <tigre20815@xxxxxxxxx>:

> I do you switch it off ? Kill switch of ignition key ?
> Using the kill switch on motorcycles with an ECU
> prevents the unit from getting information before the
> engine turns off and the information has to be
> retrieved when you start it again (hence the six
> revolutions...)

This is an old wives tale :)

>From the rat list:

GTRAT
Grand Prix 125
Cornwall, UK

Rides:
Any Triumph in the shop!!
'98 ZRX1100

Joined: May 08, 2004    Posted: 2004-05-08 15:56
The symptoms you describe are very similar to a to a prob with an '02 RS one of
our customers had a couple of months ago.

That prob was in fact caused by a vacuum leak on one of the IAC valve pipes.
The IAC valve is the valve that sits on top of the throttle bodies and goes
into the bottom of the airbox. The valve has 3 `corrugated' plastic pipes
attached between it and each intake manifold. the resulting lack of vacuum to
the valve causes the IAC to send false info to the ECM resulting in weak/rich
running depending on speed/load/throttle position etc.

The IAC is checked with the Actia (Triumph Diag Tool) and should be within a
specified range of `steps' (20-35 if memory serves me correctly).

Use of the `kill' switch is not harmful to the ECM, however, switching the
ignition off and then back on within 3 seconds could also cause your symptoms.
On all Triumph FI systems except the Daytona 600 & Rocket III, the ECM
initiates a `power down' sequence when the ignition is switched off (IAC fully
closes and opens), if this sequence is interrupted (i.e. ignition switched on)
the IAC valve loses its original starting point.

BTW the Daytona 600 & Rocket III use a power up sequence as they have a full
Keihin FI system.



--
SimonB
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