ox66 - Setting Idle Speed via TPS

[TomS]

Engine is a 1999 Yamaha SX200TXRX.

Assuming that I have adjusted the TPS correctly (5V reference voltage and .5V output voltage with throttle valves closed), and have re-connected the throttle link, can I set the idle speed according to the TPS output voltage?

I don't have a multi-meter that can pick up the engine RPM and the Yamaha gauge RPM is only accurate to +/- 100 RPM. What I'd like to do is adjust the idle speed screw to get it somewhere between 700 and 800 on the Yamaha gauge, and then fine tune it using the TPS output voltage.

I don't think there is a published spec for the output voltage at idle, but I have seen .6V and .62V referenced here in the past. Is there a better value I should use?

-- Tom

 

[JUSTINTIME]

Re: ox66 - Setting Idle Speed via TPS

rodbolt will know
i do not have that manual

 

[JUSTINTIME]

Re: ox66 - Setting Idle Speed via TPS

i will look up tomorrow for u if nobody come through

 

[TomS]

Re: ox66 - Setting Idle Speed via TPS

Justintime or Rodbolt, any input on setting the idle speed via TPS versus the not-so-accurate yamaha digital tach?

Thanks guys,

-- Tom

 

[rodbolt]

Re: ox66 - Setting Idle Speed via TPS

reread your service manual.
the TPS IS NOT used to set timing.
follow the correct linkage adjustment procedure to set the TPS idle voltage.
the yamaha digital tach is actually fairly accurate.
the TPS gives the ECU information on throttle angle opening. from there,along with other sensor inputs, the ECU compares the engine RPM with the angle and attempts corrections to fuel delivery and timing to make the engine speed correspond to a program map.
when the manual calls for throttles fully closed the easiest way to achive it is to discconect the linkage.
fully closed means just that.
all my service guides are packed in boxes now so I am hesitant to say specifics without them. old age memory really bites.
but with the throttles fully closed set the TPS voltage to its spec then use the idle speed screw to set the idle speed.
HPDI sets a bit different from OX66.
if I remember it today while fighting a pair of 8.1 osi volvos i will look it up for a memory refresher.