The same thing happened to my 2017 gen 4, it would idle just fine and run unpredictably anywhere between great and bogging when WOT. The 2017 wire harness was known to short out, either due to routing or poor insulation. The local ship replaced it with the later gen 4 wire hardness that didn't have this issue. Cost me $1300 parts and labor.

 

You wouldn't happen to know where these harnesses short out? I'm going to have to take a look at my harnesses tho.

 

that would be the question yeah. But no I have no idea. And I don't think the other shop knew either.

 

Ok well thx for the help I'll see what I can find

 

You have a pipe or can on it?

 

Yeah it's got a ggb on it, bought it with it and I don't have the original

 

Took it for a rip this evening to see if I could get a fault code to come up, there was nothing the whole time, went to park it and got P0339 which is crank position sensor. Gonna order and new one and see if that does the trick

 

There's a couple wire harnesses for your sled on Kijiji if it comes to that.

 

Yeah I'm going to change my crankshaft sensor if that doesn't do it I'll take off my harness and inspect it, if I can find anything that'll be my next step

 

Check fuel pressure! Filter, pickup or pump.

 

Do you know what the fuel pressure should be?

 

https://www.dootalk.com/posts/24535761/

44 psi. Check the post I linked for all the info you need.

 

https://www.dootalk.com/threads/bogging-and-cutting-out-at-8000-rpm-video-with-sound-inside.1561449/page-2?post_id=23156033#post-23156033

https://www.dootalk.com/threads/800-etec-bogging-issue-please-help.1575813/?post_id=23220771#post-23220771

 

My 2017 850 Etec Summit X did have shorts in the wires that feed to the injectors and so I replaced the connectors with new ones that had pigtails. However, my display would read "CHECK ENGINE" with the three beeps (annoying as all get out) until I let off the throttle. I just have the main issue (still not 100% resolved) that I cannot get full RPM out of my sled. So I keep troubleshooting...

Here is where I am looking right now. Might be worth the OP looking into how the capacitor (not the SHOT cap) aging can mess with the injectors. According to the shop manual, a bad cap can cause the following:
-Unstable or low system voltage (the 55V part)
-engine will not start
-engine is hard to start
-poor idling
-engine misfiring

Now I know that doesn't say bog, but it is an easy test with $3 worth of stuff to do.

If you are comfortable with the process, remove the cap from the front of the ECM and do the tests shown in the manual. There are two tests that can be performed relatively easy with a 300ohm resistor (I used three, 100ohm in series), an on/off switch and a 12V battery that is fully charged. Then you just need a somewhat reliable meter to read voltage. I used my sleds battery (e-start) and it read 13.02V at the beginning of the tests. Be careful, as the cap can discharge serious voltage, so always follow the manual and let it rest for at least 5 min after last start of the system (or running).

My old cap is 25% (or more) worse off than a brand new factory DOO cap (that I just got) when performing the tests on both, one right after the other. While my system voltage was in the PASS area regarding shop manual specs at 56.3V at idle, the cap test results could suggest that the old cap is aging significantly as well as rapidly. This speculation has numerous other factors that contribute, but the takeaway is that the longevity of the cap from DOO is not forever. The sleds are just getting into the possible end of effective lifespan for the caps without really knowing how it will affect the injectors as they are the most dependent on consistent voltage.

I haven't finished putting the new cap on the sled, but fingers crossed it either is better or at least no negative change than before.

 

Here is where I am looking right now. Might be worth the OP looking into how the capacitor (not the SHOT cap) aging can mess with the injectors. According to the shop manual, a bad cap can cause the following:
-Unstable or low system voltage (the 55V part)
-engine will not start
-engine is hard to start
-poor idling
-engine misfiring

Between the OP, you and me, we have three 2017s to contend with. The latest is a partially broken red/positive wire from starter to solenoid. When I get it to crank by wiggling the wire, I am seeing a voltage drop of 2+ Vdc. Before it cranks I see near battery voltage.

I have trouble every turn I take. I am hoping to get scope to facilitate the electrical. Something that I have learnt recently is those who mess with the electrical from just doing engine work, have often experienced electrical problems. I have trouble every turn I take.

Good point on testing the capacitor. Last time I did that was with an 800R E-TEC owner. At the time I was not smart enough to use a resistor to charge the capacitor.... I did use a test light for the discharge test, so that was ok. I am hoping to get a 2 channel Picoscope to facilitate the diagnostics.

The problem with the electrical is that we do not know where to look first. I think the E-TEC with regular coils offers an ease for us DYI to dig deeper. There is the 55Vdc System Voltage, one trigger/pickup coil, two ignition wires, and four injectors. That is a lot to measures to take, and we didn't even get into the eRAVE opening. I think this is something that wee need to get better at. The SDI is relatively simple. The E-TEC is in another ball game.

 

Oh, and factory capacitors are in stock at PZ, USD price was $69.90 last week.

 

Hey guys, just thought I'd let you all know what my problem was, the wire to my knock sensor (the sensor on the head between the injectors) was sitting against my secondary clutch shaft, it had worn through and was shorting out. Put some black tape on it and tied it out of the way and it runs like a top now! Thx for all the help tho guys!

 

Very happy to hear that you got it resolved and even more pleased that you came back to let us all know!
Have a great season