[woofe]

The beast will start and idle fine but dies when given throttle and typically has a backfire. What I've done so far: 1. disassembled the fuel pump assy and replaced the filter, it was filthy..... NO JOY!. 2. After further thought and research, I purchased a new OEM fuel pump assy. NO JOY!. Starts, idles fine, backfires and dies with application of throttle. 3. Watched the FL red light flash 1 time followed by 8 flashes.... 1-8 trouble code? It's been doing this all along....I just was not smart enough to pay attention. OK, maybe I'm getting smarter(or not). But this code is not listed in the manual. Any thoughts??? Any help is appreciated.

 

[shadetree]

I think that 1-8 code stands for 18 ?.

 

[SamUK]

Have you cleared the fault codes and tried again? ‘How to’ is in the factory service manual.

 

[woofe]

I was not aware that clearing the code would be required to have the 4 wheeler function. I'll check the book and do that........won't disconnecting the battery do that?

 

[woofe]

Yes, I assume that it is code 18. Not in the manual.

 

[shadetree]

Yes, I assume that it is code 18. Not in the manual.

then it will be code 1, and code 8. this is why I stay away from newer atvs..too many sensors and stuff to watch out for !..lol.

 

[Jeepwm69]

Code 8 is TP sensor low voltage.

Check your plug on the side of the throttle body.

If it's clean and firmly connected, download the FSM that VS_Goose has linked and look on page 6-23 for troubleshooting information.

 

[retro]

What year is it? You might have to reinitialize the TP sensor per the service manual. Dunno, cause I can't look it up without knowing the year? If it is an older 420, take the throttle body off and clean the standoff buildup off from the throttle butterfly on both sides before you perform the procedure.

 

[woofe]

It is a 2008 420 ES

 

[retro]

Ok, take the throttle body off and clean the standoff buildup (carbon deposits) off from the throttle butterfly on both sides before you perform the initialization procedure.

Clear all of the codes.

Initialize the TP/MAP per the instructions in section 6 of the service manual.

Let us know how it goes if you can.

 

[writegregb]

Clean idle air control valve as well when you clean the throttle body. Do not over oil the air filter. This isn’t the 80’s anymore. Lol.