Phazer is running rough at cruising speed

[Outlawgibbs]

So after a few maintenance repairs i took my 08 phazer mtx for a blast. Yesterday it ran great, fired right up this morning and hit the trails again and noticed a little bit of bogging at half throttle or better. Didnt think to much about it so i continued on and filled up with some 91 octane. Went a little farther down the trail and it bogged hard and now it runs like #*$&@ at cruising speed but idles great and works fine off trail or when just stabbing the gas for short bursts but any consistent throttle above quarter and it feels like its cutting out and firing back up with popping. It has fresh oil, new used throttle bodies, fresh gas, and fresh plugs.

 

[Ice_fisher]

I had a similar problem with my 2010 venture MP same motor it turned out to be a bad pin in a connector it drove me crazy for 3/4 of a sledding season. I know a couple of guys had poor pin connections at the ECU check the pins very carefully at the ecu for green corrosion or poor or loose alignment.

 

[Outlawgibbs]

That is a very good possibility. I was thinking its electrical but was leaning toward maybe the stator/rectifier. It seems like its not burning the fuel right or dumping to much fuel

 

[Handy]

Before going too far into this I would check your fuel. Sounds exactly like what my truck did when I filled up with bad fuel at a gas station. I had trouble maintaining highway speed and went through fuel at an unbelievable rate. I could actually see the fuel gauge dropping as I drove. I went through 16 gallons of fuel in just over 160 miles. Filled up at a different station and all was fixed.

 

[franklin]

Check the connection on the air sensor on the top of the air box. Mine did it last year one of the wires got broke some how and was not get power to the sensor and was dumping fuel in.

 

[Outlawgibbs]

I've filled up at 2 different gas stations with the same results. I did hear about the vacuum lines going to the air box from someone else as well so thatll be the first thing i check when i get home. It does seem to get worse the father i ride like its something that is heating up and malfunctioning or it could be just the excess fuel fowling the plugs as i ride farther. It made it back under its own power but it was protesting the whole way. And it still starts and idles fine but doesn't like going more than 40mph without really backfiring a lot

 

[blueironranger]

Sounds like a coil getting weak to me, weak coils will first start having issues under leaner conditions because it takes a strong spark to ignite a leaner mixture. Cruising at a steady speed is usually a pretty lean condition and where weak coils will first start showing issues.

 

[Outlawgibbs]

Is there a way to test the coils?

 

[Ice_fisher]

Yes you can check the resistance on the primary and secondary side of the coils. I don't remember the spec off hand. That said a coil may only break up when cold or warm underload and the resistance test with the ohm meter may not pick it up. Your problem sounds a lot like mine. I could of swore it need a coil they tested out good but I replaced one then the other with no resaults. I changed spark plugs, did an injector purge, drained all the fuel, cleaned the fuel pick up, fuel pressure test and compression test. Drove me nuts had the sled a part after every test ride. Checked sensors checked fuel delivery valume all tested ok. One bad wire in a connector was the problem.

 

[Outlawgibbs]

Ill dive into it this week and see what i can find. Im almost certain its the ignition cutting out and possibly only one cylinder doing it which is causing it to load up with fuel and burp it out when it comes back alive.

 

[Ice_fisher]

I forgot to mention you can fire the coils through the display in diagnostic mode 5 times and also the injectors for testing purposes. Good luck!

 

[2stroken]

I forgot to mention you can fire the coils through the display in diagnostic mode 5 times and also the injectors for testing purposes. Good luck!

So from just putting the display in diagnostic mode? No other tools required?

 

[Ice_fisher]

Correct once in diagnostic mode you can pull the coil and spark plug place near metal surface of the sled and inspect the spark the computer will pause it five times. Once you fallow the service manual to get in diagnostic it will also tell you what the numbers on the dash display represent.

 

[2stroken]

Correct once in diagnostic mode you can pull the coil and spark plug place near metal surface of the sled and inspect the spark the computer will pause it five times. Once you fallow the service manual to get in diagnostic it will also tell you what the numbers on the dash display represent.

Thanks, I knew the diagnostic feature was there and I figured it was just there for inspection, wasn't aware it could actually command things.

 

[ATV PRO #11]

About to update my ecu pin problem. With photos. It gave me a stumble problem when jumping or rough terrain (whoops) but didn't idle and had codes.
Like above, check those airbox connections. If it idles fine then that's prolly it. Had that problem in past with no codes on my 07.
Ecu issue sent me in circles and drove me nuts.
I personally don't think ecu connector was a problem on older sleds. Imho.