OX66 no cold high idle

[scofflaw]

Ohm'd the CTS and was in spec. Any other ideas ?

[rodbolt17]

what is the ign timing at idle?
what is the TPS voltage at idle?

[scofflaw]

Looks like I have some adjusting to do.

tps voltage 4.75 at idle.

Been thru the SM, don't see a section on ignition timing

Going to be putting this boat away till next Dec. Heading North...will bring more tools with me when I return. Assume I need my timing light ?

[rodbolt17]

4.75 would be the reference voltage.
the 3.1L motors use two 5V circuits from the ECU.
we still don't know what the TPS output is.
the ign timing is ECU con*****ed but will typically be in the 5*atdc range at idle.
does the ECU see the engine crank signal(12V on the brown wire at the ECU)?

there is a lot of things going on when the ECU sees the crank signal.
at cranking ign timing should be about 7*BTDC.
TPS at normal idle should output about .5v but without a model number all I can say is a generic setting for some OX66 motors.

model numbers are wonderful things.
it allows one to know WTF?

[scofflaw]

sx225txrs x107547.

Had a 5.01 ref voltage. key on, engine off
pink to orange voltage reading at idle. 4.7

Motor runs good, O2 issue between 3300 n 4000, will fix , but no biggie

No fast cold idle....90 plus in SW Fla. ...no big deal either...but would like to get it right........Thanks for your input

[rodbolt17]

there is an issue with your numbers.
they never made a sx225txrs.
the 225X and U motors for 1994 were carbed and did not use an O2 sensor.\
they used 6 carbs.
the first 3.1L EFI motor was the s225 X and U models in 1997.
1997 would have a last character of V.

[scofflaw]

This Ox is a 2001, my previous blown motor was a 94 carb.

[rodbolt17]

that would make it an SX225TXRZ.
that Z makes a huge difference.
ign timing at idle should be about 3*ATDC.
tps with shutter full closed NOT idle setting should be about .51V +or- .o1V.
what is the base ign timing at idle?
if your dropping the 5V ref from 5v at key on to 4.75 running you may have another sensor loading the circuit.
the diagnostic test lamp would help a lot about now.

[scofflaw]

My bad about the Z. This is a new to me DVM, and I might have the decimal point in the wrong spot. Will check again this AM.

How is the timing procedure done ?

[rodbolt17]

you don't set the timing.
you can check it with a timing lamp.
I would also index the flywheel to insure the piston TDC and the TDC mark line up.
if the flywheel is properly indexed(key not sheared) then ign timing is ECU con*****ed based on various sensor inputs.
that motor when started should rev to about 1100 and fall back to about 750 in N.
the fall back time will be based on CT inputs.

[scofflaw]

Confirmed tps voltage is in fact 4.7. Winky blink should point me in the correct direction ?

Just changed out the O2, we'll see how that goes today.

[rodbolt17]

I will confirm in fact that either your on the wrong wires or your TPS is so far off the timing should be close to 20*BTDC.
remember you have a 3 wire setup with a pick off voltage. black to orange gives the 5v ref.
pink to black gives the sensor return.

[scofflaw]

3 wire connector, and I'm on pink and orange. I'll go see what pink to black gives me. SM says pi
nk to orange.
Motor runs good. Does a 2 mile idle zone to river 10-1200 rpms flawless, smooth. Will hit 5500 in a heartbeat.

Does have a ragged cold start idle for a few till it warms up

[rodbolt17]

there are TWO TPS specs.
one is the 5Vref that needs to be tested PRIOR to testing the TPS output.
almost every sensor on that engine uses a 5Vref.