Pro runs bad when cold only - bad T-Map sensor?

[gman086]

My 2011 has run poorly when cold (first half hour) the past two seasons. I cleaned up the EGT sensor with no change. The sled runs great when warmed up and really crisp when coming down in elevation which seems to point towards a bad T-MAP sensor (temp, manifold air pressure (senses barometric pressure too)). Has anyone else had this problem and did a new T-MAP solve it? Any way to check it?

Thanks,

G MAN

 

[gmustangt]

Sounds like a cold pipe to me, I've noticed start of the day performance isn't there, even occasional minor bog, once pipe is hot sled runs great.

You can test the sensor by putting pressure on the sensor and taking a voltage reading, and it's going to read x voltage at y pressure, then you know it's working properly.
I can't remember the voltages off the top of my head but they can be found online with a quick google search.

 

[geo]

The only time I've had that issue was on another brand sled. It was the exhaust sensor.

On that sled the code was only thrown if the sensor failed hard wiring-wise. In this case the sensor did not work ohms wise (changing with temp) but was not shorted or broken wire-wise.

 

[diamonddave]

G, I forgot if you running a thermostat?

The EGT sensor's do fail in these. You could test it with a multimeter and a lighter. You could also test the T-map with a multimeter also.

I know Carls has told me the only time the ECU will adjust for a large swing in elevation is if you shut the sled off and allow the ECU to reset to present elevation.

Have you pulled plugs, sometimes the 2011 injectors will go rich.

 

[gman086]

DD, I never did get around to pulling the stat (plan to when I get a new head). I too was thinking about rich injectors but wouldn't they stay rich even after warmed up? Then again, I think they map it rich until the sled is at operating temp as I recall? I'll try the resistance readings and post back my findings.

Cheers,

G

 

[geo]

G, I forgot if you running a thermostat?

The EGT sensor's do fail in these. You could test it with a multimeter and a lighter. You could also test the T-map with a multimeter also.

I know Carls has told me the only time the ECU will adjust for a large swing in elevation is if you shut the sled off and allow the ECU to reset to present elevation.

Have you pulled plugs, sometimes the 2011 injectors will go rich.

That's an interesting comment about the ECU and elevation changes. Never heard that before.

 

[BILTIT]

Yup, sounds kinda fishy since we ride from 2000ft up to 8000ft at times without shutting it off. That's a large swing in my books.


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[diamonddave]

Yup, sounds kinda fishy since we ride from 2000ft up to 8000ft at times without shutting it off. That's a large swing in my books.


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When Jack Struthers speaks about Polaris sleds....people listen.

 

[rmscustom]

Interesting... I've noticed a few times if we head down without stopping I'll hit det mode once in awhile getting close to the truck... Never happens when heading up.

 

[gmustangt]

The ecu does "refresh" itself when shut off/on , also when it idles for a certain amount of time (i wanna guess 30 seconds) it will refresh itself, you will notice when you start your sled from cold after a certain amount of time the idle changes, usually drops.

You may be able to go up/down a couple thousand ft and your sled still run, as the slight variance in duty cycle is minor compared to all the variation in fuel pump, filters, injectors etc...

This issue was much more amplified in some of the previous turbos I owned as you were piggy backing a % off a %. There was times coming down from high to low elevation, sled would bog , hit the kill switch ,re start, and sled was ripping again.

If you have a any buddies with pros it would take 5 minutes out of your ride to swap TMAPS / EGT Sensors, and would answer your question 100%.

I still think as you said it only happens at the start of the day it is because of a cold pipe, coming down at the end of the day it runs good you said which would eliminate tmap for me.
The engineers would love to drop some extra weight and get that pipe insulation and cover off the pipe, but it is there for a reason. 2 strokes need that pipe hot.
Im going to ceramic coat and wrap my pipe, win/win for performance and under hood heat.

 

[Scott]

My sled has been boggy after I sit for a few mins and take my helmet off.

I'll have to drive around in circles for a bit before it comes out of it where I can stab it without it loading up or bogging.

Sometimes it will do it while going down the trail and I haven't been stopped.

I see it mostly in the 6000 rpm range. Both with gentle throttle and hard throttle.
Seems to be at almost any time of the day.


I have a fully brand new shortblock engine with about 150 miles on it and it's been doing it since I started breaking this one in at zero miles.
I also have brand new injectors at 105 miles into the new engine and it didn't help.
I also had fuel filter changed at 105 miles. That didn't help.

No codes have been thrown at all.