2007 RXP 155 N/A runs terribly when cold

[Briceybobo]

I've had this problem for 4 years and can't figure it out. It keeps getting worse. It used to be only if the ski sat for awhile. but now it is every time I start it.

When I start it the idle is extremely rough. 1600 - 2000 rpms. If I give it any throttle there is no response.

Let it warm up for a little bit and it will idle perfect 1800 rpms. But, I can't go higher than 4000 or 5000 rpms. After a while it will let me go full throttle and I won't have any problems with it unless I shut it down and try again in like an hour or two.

I'm lucky enough to have two of the same skis and can switch out parts to test different things. Here is what I have tried so far;
- MPEM
- New plugs and coils. Also tried swapping plugs and coils
- Swapped Injectors and cleaned them
- Swapped rectifier
- New fuel pump with filters
- Swapped MAP sensors

Any help would be much appreciated!

 

[Digdog]

Did you try swapping the MATS sensor? Also when you take the plugs out what do they look like?

 

[MacSeaDoo]

Another suggestion is the idle control valve. It might be failing. It operates like a screw motion to raise and lower the valve to regulate air when the throttle is closed. It is possible that when warm, it operates more freely?

 

[Briceybobo]

Did you try swapping the MATS sensor? Also when you take the plugs out what do they look like?

So I pulled the MATS sensor (green one)and ohm checked it. 76 degrees F outside and it was 1200 ohms. I pulled the one off the good ski and it was 1800 ohms. Swapped sensors and it ran rough for a minute and then seamed to run right at 1800 RPMs.

So I am going to buy a new sensor. and test it this weekend.

I did pulled the plugs and they all looked good. I ran compression on each cylinder and they were around 130psi.