Had a Question Asked to Me About HPDI NOT Idling on 4 Cylinders.........

[Jason Phillips]

Had a gentleman ask me something I couldn't answer this weekend. I was fishing a tournament and was asked what causes the HPDI's to idle on 4 cylinders, or more importantly, what would keep them from idling on 4 cylinders. The gentleman has a 250 HPDI but it's idling on all 6. You can tell that because of two things: 1) The idle is smoot and is between 1200 and 1400 rpms 2) You can rev it clear to the limiter in neutral if you want to without even a hickup. When it's on 4 cylinders it will spit and sputter if you try to give it gas in neutral.

Any ideas? I told him it's controlled electronically, but couldn't help other than that. He's taking it to the dealer, but I want to know for my own curiosity. Is there something to look for that could be unplugged or loose?

[Luke]

never heard that one either i thought that they only idled on 4 for fuel comsumption but im not really sure other than that or why it would be ideling on 6 could be something wrong with the ECU possibly

[Jason Phillips]

I don't think that was it. There's a switch on the motor that recognizes when the motor is in neutral and then signals the computer to go into 4-cyl mode. I'm guessing that's what the problem is I just didn't know where to look to show him.

[Luke]

no clue on that one bud havent heard that one before

[jm1495]

I believe it starts hitting all 6 when you put it in gear. So the cuttoff when its in neutral is propbably an electronic switch that may have gone bad.

[MD 20i]

jason, that switch went bad on my zx225. ran it like for several weeks before yamaha sent my dealer the part. if you look were the slide is on the motor were the shift cable runs, there is a little switch that is on the slide. it has a small piece of metal that goes up and done with you put it in forward and reverse. that trigers the switch

[Kenneth ALBassr]

You could always just recommend a dealer to go to so it can be fixed under warrarnty.

Kenneth

[Jason Phillips]

And as I stated in the original post......he's taking it to his dealer. I was just asking for my own information.

[JUST-IN-TIME]

it is a combo of things
the shifter interup can cause this
plug it into YDS and it with throw code 13 i think

i will get my tech notes out and post on this

[toledo freak]

the engines only idle on 4cylinders in neutral but as soon as you shift into gear it idles on all six, i believe it drops#2 and #5 in neutral i cant remember, but i'm positive of the rest

[boatmandan]

Hay freak You are right it drops #2&#5 then when ya put it in gear thay all should come on . On the stb. side back buy the shift cable it is a blue wire with blue plug it can make run like sh** when goes bad.