2018 1000-5 drops a cylinder at idle.

[Redtech]

So let me start by saying I've been a red level honda power sports tech since 2014. This one has me completely stumped though. Have a 2018 1000 5 seater that came in for 600 hr service and stalling at idle. As part of the service got new air filter and plugs. Cleaned spark arrestor and set valve clearances ( front exhaust valves needed adjusted slightly). After service I test drove and verified it would stall after stopping an letting idle. Checked fuel pressure which was good, charging voltage was good, throttle cable freeplay was good, inspectected Idle air control valve and was notch through movement and passages were fairly dirty. Replaced IAC valve and same result. Pulled plugs again and found covered in soot already. Cleaned plugs and checked injectors for leaking and spray patterns, checked ignition coil peak voltages and injector resistance, also found an old repair to front injector harness so I cut out the butt connectors and soldered in new connections just to make sure it was good. Have cleaned all grounds I can find ( 2 on engine, 1 on frame under seat, and battery). Tested battery with Honda and polaris battery testers. Everything checked out. Honda tech line told me try swapping pcm into known good machine. That checked out also, so after waiting for 2 weeks for tech line to get back to me after sending in data recordings of when it drops the cylinder I pulled in a new machine and swapped coils one at a time to rule out. Swapped injectors, Cleaned throttle body really good. All with same result, drops cylinder after a couple minutes and smells to be running very rich. Tried running with O2 unplugged an same result. Started checking everything again and decided to check for shorts to ground and ac output of stator. Found oil in stator plug of regulator and noticed when I unplugged it it ran fine. Put a battery charger on machine and it idle fine almost an hour but anytime I plug the stator back in it starts dropping cylinder an will eventually stall. I contacted techline again and we decided replacing stator and regulator would be the ticket. We'll today I replaced the stator and regulator and while bleeding the coolant I had same issue again. So I unplugged stator and it picked up the cylinder and runs good again. I'm at a loss as to what's going on with this thing. I can't for the life of me think of anything the stator would effect like that to only drop one cylinder. As far as I can tell it is dropping the front cylinder and running very rich. Anyone have any ideas I haven't thought of already?

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[Admin]

 

[DG Rider]

So let me start by saying I've been a red level honda power sports tech since 2014. This one has me completely stumped though. Have a 2018 1000 5 seater that came in for 600 hr service and stalling at idle. As part of the service got new air filter and plugs. Cleaned spark arrestor and set valve clearances ( front exhaust valves needed adjusted slightly). After service I test drove and verified it would stall after stopping an letting idle. Checked fuel pressure which was good, charging voltage was good, throttle cable freeplay was good, inspectected Idle air control valve and was notch through movement and passages were fairly dirty. Replaced IAC valve and same result. Pulled plugs again and found covered in soot already. Cleaned plugs and checked injectors for leaking and spray patterns, checked ignition coil peak voltages and injector resistance, also found an old repair to front injector harness so I cut out the butt connectors and soldered in new connections just to make sure it was good. Have cleaned all grounds I can find ( 2 on engine, 1 on frame under seat, and battery). Tested battery with Honda and polaris battery testers. Everything checked out. Honda tech line told me try swapping pcm into known good machine. That checked out also, so after waiting for 2 weeks for tech line to get back to me after sending in data recordings of when it drops the cylinder I pulled in a new machine and swapped coils one at a time to rule out. Swapped injectors, Cleaned throttle body really good. All with same result, drops cylinder after a couple minutes and smells to be running very rich. Tried running with O2 unplugged an same result. Started checking everything again and decided to check for shorts to ground and ac output of stator. Found oil in stator plug of regulator and noticed when I unplugged it it ran fine. Put a battery charger on machine and it idle fine almost an hour but anytime I plug the stator back in it starts dropping cylinder an will eventually stall. I contacted techline again and we decided replacing stator and regulator would be the ticket. We'll today I replaced the stator and regulator and while bleeding the coolant I had same issue again. So I unplugged stator and it picked up the cylinder and runs good again. I'm at a loss as to what's going on with this thing. I can't for the life of me think of anything the stator would effect like that to only drop one cylinder. As far as I can tell it is dropping the front cylinder and running very rich. Anyone have any ideas I haven't thought of already?

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Have you checked to see what it's charging at?

Is it possible that the movement of the harness by unplugging it is restoring the cylinder rather than the actual function of the stator?

Is this a dead miss, or just an "incomplete combustion event"? Most things that lope at idle, yet clear up above it tend to have valve issues (IE lower compression on that cylinder). I'm talking to you, Chrysler pentastars...

 

[Redtech]

It's not a dead mis most times, it will go into a dead mis though just before it dies. Ac output at stator is 28volts ac on all 3 legs at idle. Voltage at battery never drops below 14 volts unless it's about to die (already misfiring) and never goes above 14.6 volts while running. I've pulled on and wiggled the harness all around the area. Compression was 180 PSI on front and 185 PSI on rear cylinder. We replaced the stator an regulator thinking it was leaking ac voltage into the system causing chaos with everything. Also stator harness only has crank sensor and stator connectors. Unplugging doesn't wiggle the rest of harness at all anyway. I was going to do a hot and cold leak down test when I found unplugging stator picked up the cylinder an it ran fine. Will run great under throttle an driving. It is only at idle it drops the cylinder. I've been all over this thing an it's making me lose my mind. To top it off I had a second one come in with same symptoms now but not gonna dive feet first into it until I can figure this one out. Did verify it was same unplugging stator and it runs fine though.

 

[DG Rider]

It's not a dead mis most times, it will go into a dead mis though just before it dies. Ac output at stator is 28volts ac on all 3 legs at idle. Voltage at battery never drops below 14 volts unless it's about to die (already misfiring) and never goes above 14.6 volts while running. I've pulled on and wiggled the harness all around the area. Compression was 180 PSI on front and 185 PSI on rear cylinder. We replaced the stator an regulator thinking it was leaking ac voltage into the system causing chaos with everything. Also stator harness only has crank sensor and stator connectors. Unplugging doesn't wiggle the rest of harness at all anyway. I was going to do a hot and cold leak down test when I found unplugging stator picked up the cylinder an it ran fine. Will run great under throttle an driving. It is only at idle it drops the cylinder. I've been all over this thing an it's making me lose my mind. To top it off I had a second one come in with same symptoms now but not gonna dive feet first into it until I can figure this one out. Did verify it was same unplugging stator and it runs fine though.

Does the Honda scan tool thingy have live data? I'd be curious the see if voltages from things like the MAP sensor or TPS change dramatically after unplugging the regulator.
Just to eliminate it, could a known good regulator be swapped in?

 

[Redtech]

I guess I haven't had the mcs plugged into it since I found the unplugging stator correcting it. Will check on Monday morning when I get to work at 6. I already replaced both the stator and regulator but it's simple enough to swap with another machine again. I went back over the recording I sent to tech line yesterday and map pressure seemed normal.

 

[DG Rider]

I guess I haven't had the mcs plugged into it since I found the unplugging stator correcting it. Will check on Monday morning when I get to work at 6. I already replaced both the stator and regulator but it's simple enough to swap with another machine again. I went back over the recording I sent to tech line yesterday and map pressure seemed normal.

I was thinking bad part. Unlikely from Honda... but things ain't what they used to be for sure.

Keep us updated. Stuff like this can be maddening for a DIY guy/gal, and answers to those weird ones can be a huge help.

Also, consider being a regular. We lost our resident factory Honda tech not too long ago. We need another.

 

[Redtech]

I can sure try to be around as regularly as I can be. I love helping people out when I can. And also love fixing broken machines.

 

[Mark in Northern Iowa]

Howdy and welcome..... again from Northern Iowa
.
I told you these guys would have more ideas then just me over at the other place.
.
Have a good day

 

[ChadD]

@dakotadrone you better put some pictures of your ride on before @Remington sees you. 🤔🤣. Also welcome from Michigan

 

[DRZRon1]

It's not a dead mis most times, it will go into a dead mis though just before it dies. Ac output at stator is 28volts ac on all 3 legs at idle. Voltage at battery never drops below 14 volts unless it's about to die (already misfiring) and never goes above 14.6 volts while running. I've pulled on and wiggled the harness all around the area. Compression was 180 PSI on front and 185 PSI on rear cylinder. We replaced the stator an regulator thinking it was leaking ac voltage into the system causing chaos with everything. Also stator harness only has crank sensor and stator connectors. Unplugging doesn't wiggle the rest of harness at all anyway. I was going to do a hot and cold leak down test when I found unplugging stator picked up the cylinder an it ran fine. Will run great under throttle an driving. It is only at idle it drops the cylinder. I've been all over this thing an it's making me lose my mind. To top it off I had a second one come in with same symptoms now but not gonna dive feet first into it until I can figure this one out. Did verify it was same unplugging stator and it runs fine though.

outstanding troubleshooting data!!!!!

this one is very interesting (maddening) because it doesn't follow any logic - is there any variability to the CKP sensor that something else like the crank is moving causing the sensor not to pick up?

possibly pull all fuses that don't affect the engine running just to try and eliminate those circuits\wiring

when I run into problems like this at work with PLC systems that have thousands on sensors,

1-start isolating circuits until we figure out what is affecting a particular circuit
2-80% of the time it is an input (pressure, temp, limit, encoder, etc.)
3-19% of the time it is an output (coil, servo, etc.)
4-1% of the time (code issue, ECM\PLC brain issue)

sometimes we have to get the parts cannon out and take an educated guess as well

good luck - having 2 for the same symptom - wow

 

[Redtech]

outstanding troubleshooting data!!!!!

this one is very interesting (maddening) because it doesn't follow any logic - is there any variability to the CKP sensor that something else like the crank is moving causing the sensor not to pick up?

possibly pull all fuses that don't affect the engine running just to try and eliminate those circuits\wiring

when I run into problems like this at work with PLC systems that have thousands on sensors,

1-start isolating circuits until we figure out what is affecting a particular circuit
2-80% of the time it is an input (pressure, temp, limit, encoder, etc.)
3-19% of the time it is an output (coil, servo, etc.)
4-1% of the time (code issue, ECM\PLC brain issue)

sometimes we have to get the parts cannon out and take an educated guess as well

good luck - having 2 for the same symptom - wow

Tomorrow morning right away I'm gonna hook up the mcs and watch live data while unplugging the stator.
That crank sensor is part of stator assembly an was replaced with the stator and regulator. I absolutely hate firing parts cannot at customer machines.
You're right on it doesn't follow any logic for me. I've been in the powersports tech field for 15 years now as a multi-line dealer technician. We sell an service something like 10 different manufactures, an this may be the oddest issue I've had so far. I have a few snap shot recordings of the issue happening an the only anomaly I can find is map pressure spiking to boost just before it dies, but I believe that was caused by a slight back fire when it popped through the front cylinder intake as it coincides with the timing retarding as it tries to keep itself running.

 

[Jerryg]

Sounds a little like an experience I had with a Honda EB6500 I had years a go. It would immediately trip the GFCI. Turns out there was a soldered wire inside the main harness that was slightly protruding and touching the inside of the control panel.

Maybe wire harness?

 

[Redtech]

Sounds a little like an experience I had with a Honda EB6500 I had years a go. It would immediately trip the GFCI. Turns out there was a soldered wire inside the main harness that was slightly protruding and touching the inside of the control panel.

Maybe wire harness?

Thats what I'm dreading honda is gonna tell me to replace next. I've tried almost everything else I can think of. We have seen a small handful of harness issues on these. I feel much better about a job like that if I can track down and isolate the exact circuit that is causing the issue. Since it's a 2018 Honda is not covering repairs but the field service guy I've been talking with has agreed to goodwill some of my diag time. That only covers about half of the time I have trying to chase this down. Not to mention the time and parts of replacing what I thought the issue was. The life of a tech I suppose.

 

[Jerryg]

Maybe before replacing a harness, chase the the harness from the stator to where ever it goes.

 

[Redtech]

Maybe before replacing a harness, chase the the harness from the stator to where ever it goes.

Thats what I was looking at end of day Friday when I left for the weekend. As far as I could tell the power wire goes straight from regulator to the battery cable. Still have to dive into the harness diagram deeper to figure out where all the ground wire side of regulator connector goes. I'm not jumping the gun and throwing a harness at it unless absolutely necessary. They are expensive and not much fun to replace. That's why I joined here to bounce around ideas an see what I was missing that someone else would think to check. I've got a few leads to follow tomorrow morning now and see if that gives any clues.

 

[Jerryg]

Thats what I was looking at end of day Friday when I left for the weekend. As far as I could tell the power wire goes straight from regulator to the battery cable. Still have to dive into the harness diagram deeper to figure out where all the ground wire side of regulator connector goes. I'm not jumping the gun and throwing a harness at it unless absolutely necessary. They are expensive and not much fun to replace. That's why I joined here to bounce around ideas an see what I was missing that someone else would think to check. I've got a few leads to follow tomorrow morning now and see if that gives any clues.

Good luck, let us know how you make out.

 

[P1K5Dave]

I can't help, but I just wanted to say that you've done a great job of troubleshooting the problem and I admire that you're not shotgunning parts at it. You've got to be >< this close to figuring this one out, and the guys here will be a great resource!

Be sure to keep us updated. Solving it and documenting it here will be a great help to someone, sometime.

 

[Redtech]

I can't help, but I just wanted to say that you've done a great job of troubleshooting the problem and I admire that you're not shotgunning parts at it. You've got to be >< this close to figuring this one out, and the guys here will be a great resource!

Be sure to keep us updated. Solving it and documenting it here will be a great help to someone, sometime.

I appreciate that, just have this sinking feeling it's gonna end up being something super dumb that once it's found. Won't be able to believe how I could've missed it. Hope that's not how it ends up but if it does that's life. Live, learn, do better the next round, and repeat.

 

[DG Rider]

Speaking of potentially bad harnesses, if you get some free time, check out this 700 thread.

P700 - EPS recall done + fuel pump. Now it dies when driving.

Got my 19' 700 back from dealership yesterday. It stalled twice at idle in the dealership driveway. EPS Light came on both times. Could not get it to die a third time, EPS Light was off on restart. Against my better judgement, I brought it home. It died 5 times in 3 miles, varying RPM/SPEED...

hondasxs.com

It's a long read, but just curious if You've seen this before.

 

[Cobber4082]

First off let me say I don't claim to know dick... but since it seems related to stator/charging/load at idle could it still be ground related? Try running an extra known good ground (jumper cable clamped at appropriate locations)
At least it would positively eliminate 1 possibility.