2002 SX150TXRA Idles too fast

[ksmillie]

I just got my motor our of long storage.
motor was slow to start at first but got that all cleared up.

Now it starts instantly but idles about 1500 - 2000 RPMs.
I have checked all linkage and it is bottomed out. (low as can go).

I cannot hear anything click when the choke is held down (on key at controls).
I am wondering if my choke is stuck but I cannot find a choke actuator on the motor, does it have one?

The butterflies on the intake are all closed tight, they open when throttle up.

I found a lot of unburned fuel in the bottom of the intake cover (Plastic shroud on front of motor)

I do not see any vacuum lines, are there any on the fuel injected Saltwater series II ?

I cannot figure out what is wrong. I am a pretty good wrench who typically fixes every problem I have but this one has me stumped.

[boscoe99]

Your model is fuel injected. There is no choke.

You may have a standalone choke toggle switch or a push to choke key switch at the dash but it serves no function whatsoever.

[DennisG01]

My SX250 idles high on the hose for quite some time, but eventually gets down below 1,000. In the water, it idles much better in a shorter amount of time. From my experience, most 2-cycles idle a little funny on a hose since there's no backpressure on the exhaust.

[ksmillie]

Your model is fuel injected. There is no choke.

You may have a standalone choke toggle switch or a push to choke key switch at the dash but it serves no function whatsoever.

Thanks, that confirms what I thought

[ksmillie]

My SX250 idles high on the hose for quite some time, but eventually gets down below 1,000. In the water, it idles much better in a shorter amount of time. From my experience, most 2-cycles idle a little funny on a hose since there's no back pressure on the exhaust.

I would like to think this is correct but, I have ran my engine on the hose in the past and it is definitely idling much higher than usual.
In the past, I could shift in and out of gear pretty smoothly, it is shifting hard with the increased RPMs, as in slamming into gear.

I have done some research and I see that maybe the low pressure fuel pumps could cause this...how is beyond me, I would expect a low idle with poor LP pumps.
I also see that faulty injectors may cause it, but I am leaning towards something else.

As for vacuum lines, I have looked at the diagrams further and indeed there are a couple of vacuum lines above the fuel injection Pump (VST) and connected to the pressure regulator. I will check these connections and see if I have any vacuum leaks.

Thanks for the feedback

[DennisG01]

Oh well, it was worth a shot!

Without knowing too much about these engines, I would lean towards vac lines, as well. Do you have a fuel pressure gauge - haven't had a need to do it on my motor, yet, but I suppose that could at least tell you if you're getting proper pressure? I think it's like 35-ish psi. Although that might be going in the wrong direction since I doubt you would be running high RPM with low PSI, right?

I don't have my manual with me right now, but does it say anything in there about testing procedures for vac lines, etc?

[ksmillie]

Oh well, it was worth a shot!

Without knowing too much about these engines, I would lean towards vac lines, as well. Do you have a fuel pressure gauge - haven't had a need to do it on my motor, yet, but I suppose that could at least tell you if you're getting proper pressure? I think it's like 35-ish psi. Although that might be going in the wrong direction since I doubt you would be running high RPM with low PSI, right?

I don't have my manual with me right now, but does it say anything in there about testing procedures for vac lines, etc?

I do have a pressure gauge...but I don't have the manual, I was just looking at the engine diagrams on this site

[rodbolt17]

quit hunting wabbits and chasing ghosties.
simply google open loop speed density EFI operation and figure out what is wrong.

when cold the ECU advances timing and adds fuel.
does the ECU see the CTS?
is the CTS working?
until the ECU "sees" the engine above 113*F its stays in warm up mode.

O2 sensor feedback is not used.

[DennisG01]

Just because it's fun to learn, I googled, too. I didn't know what CTS was, but after doing some reading, is it a Coolant Temp Sensor (water temp sensor)?

[rodbolt17]

CTS is indeed a coolent temp sensor.
if there are any faults or sensor failures,other than O2, it advances base timoing to 7*BTDC and adds fuel.
means it idles fast.
does about the same for cold starting.

[boscoe99]

I suspect that we are talking about the engine temperature sensor. AKA thermosensor.

Some seem to measure water temperature and some seem to measure actual block temperature.

Would be nice if we could standardize on terms but that won't happen. Not in my life time. Hell, it seems the further we go the further apart we become.

[DennisG01]

Would be nice if we could standardize on terms but that won't happen. Not in my life time. Hell, it seems the further we go the further apart we become.

I still struggle to understand when my wife sends me texts with all of these abbreviations and hieroglyphs. I keep telling her - you have a FULL keyboard on that phone - just type it out! But I guess those 4 seconds she saves is worth it.......

[boscoe99]

I still struggle to understand when my wife sends me texts with all of these abbreviations and hieroglyphs. I keep telling her - you have a FULL keyboard on that phone - just type it out! But I guess those 4 seconds she saves is worth it.......

I have read that the younger generation does not want to use phones. Of any kind. They want to text everything. In hieroglyphics as you point out.

I am old enough to remember letters being the prime mode of correspondence. In baskets and out baskets. First fax I saw used thermal paper. We thought they had reached the end of the technological line.

[DennisG01]

Boy, it HAS been a long time! I remember my father coming home with this "thing" for our computer when I was about 12. It was something called a "hard drive". It was 12"x12"x4" and had something inside about the size of a record (just saying "record" dates me...). It held an ENORMOUS amount of data - a whole megabyte of data! I remember thinking "Who would EVER need that much storage?". It was $400.

[rodbolt17]

and I remember in my late 20"s. apple II was the rage.
and the control puter on the CIWS on the USS Arleigh Burke was a TRS 80.
I can remember when playing battle chess took four discs.


however if ANYONE can get me a usable copy of Chips Challenge I will be gratefull.