Pro 800 ECU interchangability

[Bushwacker1]

I have a 2011 800 RMK that is cutting out after a run up to 8000 rpm. Sometimes it does it right away and sometimes it takes around 10 seconds. It runs strong to 8000 drops a thousand or so RPM. I have checked the power valves, solenoid, and stator and they all check out ok. It had a code for overvoltage to the pipe temp sensor and it failed. I replaced the sensor and the voltage regulator and it is still acting up. I have a known good 2013 ECU that looks like it will plug in but need know if anyone knows if you can just plug it in and not have to have it reprogramed.
I am also going to change the fuel filter and inspect the fuel pump lines and pick ups. Any other suggestions on what to look for are welcome.

 

[boxster7614]

No you cannot use a 2013 ECU. 2011 used different injectors, the first injectors were Blue and the updated were Yellow. The ECU must match the color code to injectors, there should be a sticker on the back of the ECU with code. I recently had starting problems with my 2011, I updated to the Yellow injectors which I bought used and had sent for cleaning and flow check. I also purchased a Yellow ECU, it didn't make any difference. Turned out to be a bad fuel pump; changed the pump, fuel filter and in tank fuel pickup which was completely disintegrated. I just made a post on this a few days ago. First thing I would suggest is change your fuel filter you may be starved for fuel.

 

[Bushwacker1]

Thanks for the reply. I saw your post and thought it would be a good idea to take a look at those lines and replace the filter. I hope to take a look later tonight or tomorrow.
I think mine has yellow injectors but I will need to check to be sure what is in there. I also have a set of blue injectors that came with the sled in a box of parts so things have been changed along the way.
So can a dealer reprogram an ECU to different color injectors?
So it sounds like a 2013 ECU work on a 2011 as long as the correct color injectors are installed?
If I find I do have yellow injectors I would like to have the option of using the good 2013 ECU for testing as long as it is compatible if the fuel filter does not fix it. As most my testing and troubleshooting will need to take place hundreds of miles from the house I need to be sure to have a plan b c and d to try to get this issue resolved.

 

[Octanee]

I had some issues with 1 of my 2 2011's, I swapped ECM's and neither of them would run right, one was certainly lean and the other rich, again both programmed and dotted for yellow, and harness, and injectors the same. Also IIRC the 2012 injectors wont fit the 2011 cylinders as in 2012 they made a slight casting change up for the injectors the way they sit.

That said, I believe you otherwise *could* put a 2013+ ecm on the sled but you need the gauge as well, but that was from a turbo standpoint that the ecm would be reflashed for a turbo so may not apply to n/a.

 

[boxster7614]

No you can not use a 2013 ECU unless it is reprogrammed, which seems to cost more than a used ECU off eBay. My research from part searching is that in 2012 they changed from Siemens to a Bosch injector, and in 2013 they changed the injectors again. The fuel rail seems to be the same part number, however in 2013 injectors have two plugs on the harness instead of just one. So after 2013 you would need to update the wiring harness to 2013 injectors along with reprogramming the ECU to match.

 

[gopher-it!]

I own a 2011 and if your light on your weights or too tight on your helix
it will cut out . It was always intermittent so I thought it was fuel, electrical so on and so on.
That ecu is a real bugger and sensitive to fast rpm changes.

 

[Bushwacker1]

Just to clarify this sled has a custom big bore kit with improved porting in the transfers with the lighter AXYS pork chop crank installed to increase case volume. There was welding done to the cylinder to add material to allow the transfer ports to be made larger than a stock cylinder would allow. This sled ran well last year for the previous owner so I am looking for whatever had changed from last year to this year to cause this RPM drop issue. Pulled the fuel filter and found it had some restriction when compared to a new one. Replaced it and did some testing. Now my problem came in @ 7600 rpm instead of 8000. The air fuel gage was showing it was rich when this happens. Ran it for a while and adjusted fuel flow on the boondocker box. Took some fuel away from what I had added from the stock setting. I got the issue to stop but now the engine top rpm was 7600 (this engine was found to pull the most weight @ 8000 rpm last year). Switched fuel settings back to stock (even leaner) and found no difference. Ran out of time so I loaded up and came home. Had some experienced help yesterday to do some testing in the shop on the stand (no snow at home). Took out the 2011ECU and replaced it with the 2013 ECU I had. Problem still there so my ECU was not the cause. Left the 13 ECU in and continued testing. We found that the engine would drop rpm at certain points and the air fuel gauge indicated a rich mixture when this happened. Took fuel away in those areas and now it seems to be running well, at least on the stand without load on the engine. I hope to get back on some snow to see if current fuel settings will work when riding. What is surprising to me is that we took fuel away in the higher rpm ranges from the stock settings right where I would expect a larger bore engine would require more. Mabey the improved porting works with the pipe better to use the fuel for more combustion in the cylinder to make power opposed to burning it in the pipe where it is waisted ? As for the cause of original problem I still can not say for sure but the fuel filter may have been restricted last year when the sled was tuned and then became more plugged when ran first thing this year causing the fuel flow curve to change drastically from low rpm to the higher rpm. Unfortunately last years fuel settings were lost when adjustments were made in haste when this issue started so I have no reference point to compare to. I have been taking notes now to be able to come back to any previous settings. This is my first time using a boondocker fuel box and an 0-2 gauge but once you get familiar with them they allow you to tune very specific areas of rpm and throttle position. The hardest part is being able to read the gauge and know what rpm and throttle position you were at for that reading, especially while trying to drive the sled down a trail safely. Learning to feel and hear the sound of a lean or rich condition is also a complete science that there is no text book to learn it from. More testing, tuning, and learning ahead.

As far as the question that started this post on interchanging a 2011 ECU with a 2013, I would say for now as long as you have the correct injectors for the ECU you are swapping to they are interchangeable.

 

[Bushwacker1]

We were able to get on some snow this weekend. Did some testing on a lake with fresh snow and found it to be rich in lower RPM ranges. Made some more changes to remove fuel there. Put the original ECU back in and confirmed it was not my original issue as it ran fine with that ECU also. Did some trail ridding and found a burble rich spot in the 4k to 5k range so made some more adjustments there. I was impressed on how hard this big bore pulls. Anyone looking for a spare ECU maybe for a turbo reflash ? I guess now I have a spare for sale. My good friend Jim was instrumental in getting this thing worked out and pushed/ taught me to do a lot of the tuning instead of just doing it for me. It was a great learning experience for me and I am glad he was willing to give up his time and share his knowledge with me. Also would like to thank whoever posted all the info on making an 5 volt power source to set a TPS sensor in other parts of the snow west forum. I was able to purchase the needed parts and make one and used other info found on snow west to test and adjust my TPS on this sled early on when troubleshooting. Just glad we were able to get this thing running like it should.