P1000 2018 P1000-5 Deluxe Running on 1 cylinder - Solved - Bad PCM

[Neohio]

 

[Admin]

 

[JMynes]

I would check valve clearance just to rule that out. Then compression test again. Might squirt some oil in the cylinder to see if that changes compression numbers (ring check).

 

[JMynes]

Another thought…
The difference in compression numbers could be due to raw fuel washing the cylinder wall clean of any oil.

 

[JLR]

View attachment 318541

Great info - thanks for the post. I tested with the engine cold, around 32 deg. The procedure calls for 'normal operating temperature' which likely accounts for my low readings. I'll let it warm up tomorrow and try again. Valve clearance next.

 

[DRZRon1]

since the cylinders are fairly even, you are good IMO

valve clearance and for a sanity check, check timing while valve cover is off

 

[JLR]

Alright - valve clearance complete. Both intake valves were good and both exhaust valves were tight. I've adjusted these and performed another compression test. With a cold engine the rear cylinder came up to 125 and the forward stayed at 95. I started it up and let it idle for a while but the smoke coming out of the exhaust was too much and I did not let it come to full temp however the engine certainly warmed up. I retested and got 142 on the rear cylinder and about 112 on the forward - I think JMynes might be correct with the fuel washing the oil film.

The plug is wet when I take it out as if its getting TOO MUCH fuel at idle. I checked spark again on both plugs and it looks good.

I tried one other thing that might shed some light on things - as stated, with the engine idling if I pull the rear plug it will sputter a bit and then die but this time I tried giving it just a little gas to bring up the RPMs and pulling the rear plug at the same time. The machine WILL continue to run on the forward cylinder alone if I hold down on the throttle a bit.

Not sure where to go from here...

 

[Neohio]

pull your skids, inspect all your wiring for rodent damage. if it sat outside the dealership for an unknown amount of time, who knows what may have moved in.

 

[Neohio]

Also, sit down and read this thread.
It was a tough pill for the OP to swallow,

P1000 - Idle issues (video inside)

So off and on over the last few weeks I've dealt with some idle issues. Some days (yesterday) are worse than others but for the most part it happens daily. I can start it and the idle will fluctuate up and down to the point that it will almost shutoff with a strong rich smell. If I put it in...

hondasxs.com

 

[JLR]

Also, sit down and read this thread.
It was a tough pill for the OP to swallow,

P1000 - Idle issues (video inside)

So off and on over the last few weeks I've dealt with some idle issues. Some days (yesterday) are worse than others but for the most part it happens daily. I can start it and the idle will fluctuate up and down to the point that it will almost shutoff with a strong rich smell. If I put it in...

hondasxs.com

That is a good read - All the fuel has been changed in my machine with no change, I've also never had it in very much water, just barely floor level last summer but that is deep enough to submerge parts of the main wiring harness...

 

[P1K5Dave]

There was another thread in here where a guy had his exhaust glowing red from one cylinder not firing. I can't remember if there was a resolution or not, but it was in the past year.

Familiar to any of you? I'll see if I can find it.

 

[sHoRtBuSseR]

One thing to try is to unplug the injector on that cylinder and keep it running for a bit. See if that cylinder dries up or stops getting wet. It's not uncommon for gasoline fuel injectors to stick open and leak constantly. If it's possible to remove the injectors and visually look at them while cranking, you can eyeball it and see if they look to be spraying the same. I'd almost guarantee it's simply an injector issue. The injectors are probably low side driven, so if your injector harness was shorted to ground somewhere it's possible that injector is wide open any time the key is on. Curious to see what you end up finding on this one.

 

[Rs1000]

Pull the seat off and get to the frame grounds behind where ecu is mounted. Kinda hard to see but find it take it off clean and put it back on.

 

[Rs1000]

Pull the seat off and get to the frame grounds behind where ecu is mounted. Kinda hard to see but find it take it off clean and put it back on.

Those grounds are directly behind your calf on your leg if sitting in pioneer. There's multiple grounds mounted in one spot there and it completely fixed mine.

 

[JLR]

One thing to try is to unplug the injector on that cylinder and keep it running for a bit. See if that cylinder dries up or stops getting wet. It's not uncommon for gasoline fuel injectors to stick open and leak constantly. If it's possible to remove the injectors and visually look at them while cranking, you can eyeball it and see if they look to be spraying the same. I'd almost guarantee it's simply an injector issue. The injectors are probably low side driven, so if your injector harness was shorted to ground somewhere it's possible that injector is wide open any time the key is on. Curious to see what you end up finding on this one.

The injector running wide open when the key is on would explain the issue if that’s the case. I have tried u plugging the injector while running and the computer senses the open and shuts down the machine for protection giving a code. I also went through all injector wiring as per the procedure in the maintenance manual and it all checked out for both cylinders - following that I swapped injectors and the issue remained on the same cylinder. I wonder if there is a wiring issue on the upstream side of the PCM? I know it puts out separate signals to each injector but does it receive separate signals from the throttle body or RPM mag pickups? I would think that could be ruled out if it takes a common signal and computes separate outputs to each injector… I tried looking through some of the wiring diagrams for that but had a hard time tracking it down. I need to confirm this.

 

[JLR]

Those grounds are directly behind your calf on your leg if sitting in pioneer. There's multiple grounds mounted in one spot there and it completely fixed mine.

Are these the grounds on the frame or on the engine? I’ll check these out, thanks.

 

[tracy guy]

Did they mess with the valves ? Adjustment takes a real pro. Try another dealer.

 

[VonHarvester]

I had an idling issue with my TalonX and the problem turned out to be the IAC valve. Fairly simple fix for about $75.

 

[JMynes]

@JLR did you get this resolved?
Inquiring Mynes wants to know…

 

[JLR]

@JLR did you get this resolved?
Inquiring Mynes wants to know…

The short story is no, it is still not resolved. That said, I should have an update in a couple days - it is looking to be a bad PCM as I have suspected. More to follow!

 

[JLR]

Alright - I FINALLY got my machine back on Thursday. I reluctantly ended up taking it back to the dealer after doing all the previously mentioned troubleshooting since I had to go away for work and wanted it resolved. After studying the electrical drawings and reading up on fuel injection I kept coming back to the PCM as the only logical thing that could cause the issue in one cylinder and not the other - all the input sensors that the PCM uses to calculate a outputs are common so there was no reason a bad sensor would only impact one. It seemed to me that one injector was getting a signal for full pulse width while the other was getting the correct signal. At one point over a month back I called and got a quote on a new PCM but asked them to connect their diagnostic tool and compare injector pulse width for both cylinders at idle and see what the PCM was doing. There was a lot of back and forth on this and I never actually got a clear answer that they actually did as I requested but they ended up taking another Pioneer of the same year in on trade and tried swapping PCMs. The problem immediately went away and would return when the original was reinstalled. Once this was confirmed, a new replacement was ordered, installed and I am finally back on the trail - needless to say my tires are back on and the tracks were spared a season of wear and tear.

The only reasonable explanation I can come up with is that the PCM was somehow damaged due to a short, or surge, while the machine was jump started since the starting battery was bad and did not get replaced to begin with. I am a bit surprised that a code was never thrown due to the deviation. I do think it should have been pretty apparent when viewing the system live through a diagnostic tool but without ever seeing this for a pioneer its hard for me to say.

I really appreciate the feedback and troubleshooting support that everyone has provided - I am not sure how likely it is that anyone else encounters this same scenario but if they do, I hope this thread will help them to have considerably less down time than I had!