P1000 Rough running and running rich. Help!

[Wyoming307]

2020 P-1000

Hey fellas, parked the Honda the other day, when back out to the shop next morning and I must have left something on because battery was dead. Charged it up and battery is good, but now the machine will run good for a bit then clunk and drop to 200ish RPM. Then idle back up couple seconds later and does this repeatedly. Cruising down the road it sounds like timing is off and missing then clears up and runs fine. And it does this every 20 seconds or so. Changed plugs, one was burnt and one looked new. Cleaned the air/fuel/idle sensor. Dealer ship has no idea nor do I want to donate hundreds of dollars for possibly nothing. Anyone have any place to start? It also runs rich now that this problem has occurred.

 

[Admin]

 

[DRZRon1]

have battery tested - these things are voltage sensitive - before anything else need to make sure there is a good strong battery - IMO

 

[Hello_Darkness]

2020 P-1000

Hey fellas, parked the Honda the other day, when back out to the shop next morning and I must have left something on because battery was dead. Charged it up and battery is good, but now the machine will run good for a bit then clunk and drop to 200ish RPM. Then idle back up couple seconds later and does this repeatedly. Cruising down the road it sounds like timing is off and missing then clears up and runs fine. And it does this every 20 seconds or so. Changed plugs, one was burnt and one looked new. Cleaned the air/fuel/idle sensor. Dealer ship has no idea nor do I want to donate hundreds of dollars for possibly nothing. Anyone have any place to start? It also runs rich now that this problem has occurred.

If it's just 1 plug fouling it's probably a bad PCM, something in the injector circuit hangs the injector open or fires it at the wrong time and it drops that cylinder.

 

[Wyoming307]

have battery tested - these things are voltage sensitive - before anything else need to make sure there is a good strong battery - IMO

I thought the same thing so I purchased a brand new battery, fully charged it and put it in. No change.

 

[Wyoming307]

If it's just 1 plug fouling it's probably a bad PCM, something in the injecteo circuit hangs the injector open or fires it at the wrong time and it drops that cylinder.

Would that cause it run bad for a bit, then clear up and run good for a bit?

 

[Hello_Darkness]

Would that cause it run bad for a bit, then clear up and run good for a bit?

They'll typically be ok under load, but idle poorly and very sporadic. Sometimes they'll seem to idle fine, especially when cold but get worse as they warm up.

 

[Wyoming307]

They'll typically be ok under load, but idle poorly and very sporadic. Sometimes they'll seem to idle fine, especially when cold nut het worse as they warm up.

You nailed it! Swapped with a buddy’s machine and runs like a top. Called the dealer to order a new one and apparently it is a common problem. Thank you for the input!

 

[Wyoming307]

Would there be a difference in part number on those pcms? I know there are different numbers, just don’t know if the different part numbers make a difference.

 

[DRZRon1]

Look up on the Honda oem parts online (Ron Ayer’s for example) and it will show exact part number for your year - and you will also be amazed at the cost as a bonus !!!!

 

[DRZRon1]

If it's just 1 plug fouling it's probably a bad PCM, something in the injector circuit hangs the injector open or fires it at the wrong time and it drops that cylinder.

Good stuff !!!!

 

[Wyoming307]

Local dealerships want $375. Ron Ayer’s price was $260! Thanks for the pointers. Hopefully the rig will be back up and running soon now.

 

[Jdiesel350]

Local dealerships want $375. Ron Ayer’s price was $260! Thanks for the pointers. Hopefully the rig will be back up and running soon now.

I'm troubleshooting the same situation unfortunately. Parked the machine for a couple months after hunting season, went to start it and the battery was dead. Jumped it but the battery was no good as it was the original 2019 and was running rough due to low voltage. Replaced the battery and still is running rough. Replaced the plugs and found its missing on the front cylinder. swapped coils, fuel injectors, cleaned IAC, checked valve adjustment, and its still missing on the front cylinder and running rough, idling poorly and stalling out. Both plugs are black and its running rich/out of time. I've been concerned the low voltage messed up the pcm the whole time. Did the the new pcm get you back up and going? Thanks

 

[Wyoming307]

I'm troubleshooting the same situation unfortunately. Parked the machine for a couple months after hunting season, went to start it and the battery was dead. Jumped it but the battery was no good as it was the original 2019 and was running rough due to low voltage. Replaced the battery and still is running rough. Replaced the plugs and found its missing on the front cylinder. swapped coils, fuel injectors, cleaned IAC, checked valve adjustment, and its still missing on the front cylinder and running rough, idling poorly and stalling out. Both plugs are black and its running rich/out of time. I've been concerned the low voltage messed up the pcm the whole time. Did the the new pcm get you back up and going? Thanks

The new pcm fixed it! Be sure to check part numbers on your pcm. Hope you get her going again!

 

[DRZRon1]

another Internet support success - Honda tech is awesome -

I’ve been down the same road on a Honda rubicon atv - spent countless hours teating everything to prove it was the pcm


frustrating but that’s part of the game

 

[Hello_Darkness]

another Internet support success - Honda tech is awesome -

I’ve been down the same road on a Honda rubicon atv - spent countless hours teating everything to prove it was the pcm


frustrating but that’s part of the game

And I apologize for not being more of a help on that diagnosis.

 

[DRZRon1]

And I apologize for not being more of a help on that diagnosis.

you do this every day and get everyone pointed in right direction - appreciate all you contribute and learning all this stuff from the pro’s like you 👍

 

[Jdiesel350]

Thank you very much for the info i'll get one ordered!

 

[Jdiesel350]

Just wanted to let everyone know that I got the new ECU installed and it runs great!! Thanks again!!