Re: [St] Still have cold start problem

[JES_VFR <jes_vfr@xxxxxxxxxxx>]

At 03:12 PM 3/28/2008, you wrote:

>A will back I made the post below. Basically I was having to give the
>bike a bunch of throttle to get it started and then it would not idle
>until it was warmed up. Once warmed up the bike runs fine. I removed
>the stepper motor and the plunger was a bit dirty so I cleaned it and
>put everything back together. This did not really help with the
>problem.
>
>So I assume either the stepper motor is dead or one of the three
>sensors mentioned below is. I know the coolant temperature sensor is
>OK as the gauge works. I assume that if either of the intake air
>temperature and pressure sensors were bad the bike would not run well
>once warmed up and/or the MIL light would be on. This is a 1999 ST
>with 49,000 miles on it.
>
>I am tempted to just buy a new stepper motor. Can anyone offer any insight?
>Rupert

Have you tested the stepper motor at all?
You say you are going to replace the stepper motor, but you don't 
really have any conclusive proof that it is bad.
If you add in the fact that the motor idles fine when it gets warmed 
up and I begin to question your diagnosis.
If the stepper motor was bad, I would think that the bike would not 
idle well period.
I would think that there is more to the idle strategy of the EFI than 
just those three sensors and the stepper motor.

I would pull the stepper motor, cover the whole, prop open the 
throttles a crack and start the bike. See if the stepper motor moves at all.







JohnS
A Dragon Ascending
"Forging my body in the Fires of my Will"

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