65 replies to this topic

[combanx]

I had exactley the same problem just yesterday....I had a post just below yours...I had brand new plugs and put them in last week. Drove the sled for about 15-20 minutes total. The other day my son drove slowly acrooss our front lawn and then shut it off. The next morning I got up and it was very cold, I thought... Oh I should go and start the sled so the battery does not die on it. Took it started fine and left it for about 5 minutes max then it started to make small back fire or popping noise. I reved it up a little and then it started to spudder, muffeled poof sounds and then died. I re-started it and again same thing, finally it did not start . I took out the plugs and they looked new, just were a liitle wet I guess from trying to start it. Cleaned them up and wiped them down ....same thing. This morning went out there put new plugs again and started up right away. Took for a ride no problems...
Try the plugs...

Paul

[phart_2005]

Mine has always done this. When it is still warming up, between 5000-and 5500 rpm, and low throttle it does this exact thing. I think it is a 'bad spot' in the fuel map when the sled is in warm up mode because once it is hot and been running for a while, it doesnt do it. If i stop for a few minutes, and it cools off, it goes back to doing this until I 'clear it out' and get going again.

I have just worked around this by blipping the throttle until I can get up to speeds and run around 6000RPM where it just goes away.


It is not the muffler temperature sensor. This sensor is only a safety to put the sled into safe mode if the muffler gets over temp, which SDIs tended to do. It has absolutely nothing to do with the closed loop fuel management system and is not causing this problem for you.

[CanUDoo]

check the fuses on the block below the lights. pull each one and clean em up, put some dielectric grease on and re-install. I had the same problem low idle; backfire sputtering. Replaced the fuses and no problem since. Check on the forum there is more on this issue for the sdi's. Good luck.

[mikieday]

well today we were working on it and i did check the sensor in the muffler and it read 199 oms ... when we unpluged that muffler sensor it still poped but not as bad and it seemed to run a bit better but still popping.road it for about 1/2 hr so it got good and hot and ran fine but it was just popping..it did eat the pull rope side plug (and has ate that side a couple times over last season and this season)

i dont know what else to do...the fuses look clean ...i have moved the resistors around...i thought maybe that o2 sensor in the pipe mite be it since the reading was lower then 220oms????

[mikieday]

Mine has always done this. When it is still warming up, between 5000-and 5500 rpm, and low throttle it does this exact thing. I think it is a 'bad spot' in the fuel map when the sled is in warm up mode because once it is hot and been running for a while, it doesnt do it. If i stop for a few minutes, and it cools off, it goes back to doing this until I 'clear it out' and get going again.

I have just worked around this by blipping the throttle until I can get up to speeds and run around 6000RPM where it just goes away.


It is not the muffler temperature sensor. This sensor is only a safety to put the sled into safe mode if the muffler gets over temp, which SDIs tended to do. It has absolutely nothing to do with the closed loop fuel management system and is not causing this problem for you.

mine cleans up a bit when its warm but it is still doing it after its plenty warm..

[heckhole]

well today we were working on it and i did check the sensor in the muffler and it read 199 oms ... when we unpluged that muffler sensor it still poped but not as bad and it seemed to run a bit better but still popping.road it for about 1/2 hr so it got good and hot and ran fine but it was just popping..it did eat the pull rope side plug (and has ate that side a couple times over last season and this season)

i dont know what else to do...the fuses look clean ...i have moved the resistors around...i thought maybe that o2 sensor in the pipe mite be it since the reading was lower then 220oms????

What do you mean by eat the mag side plug? Melted? Electrode missing?

[mikieday]

What do you mean by eat the mag side plug? Melted? Electrode missing?

just fouled it..no damage to the plug

[mikieday]

im going to try and get video of the poping or audio..not sure how to post it but i will try

[robinap]

X2 on not needing exhaust probe it will run fine with or without sensor even unplugged with check engine light on it should still run good. Id run the appropriate ratio of seafoam in fuel to help clean injectors. It make take a little seat time to get it running top notch. Ive seen the same thing and blamed it on injectors . The seamfoam worked for me.

[Shrek607]

I have an 04 600 HO SDI. I just put in the VForce reeds and carb boots and I am having the same popping/backfiring issue. It seems like it does not want to idle. I put 75 miles on this weekend thinking I could run it and clear up the problem but no luck it still pops/backfires. My buddy thinks it is bad gas. I put fresh gas on top of the gas from last season. I have done this every year in the past as I put stabil in at spring time and I have never had a problem. I plan on putting all fresh gas to check his theory, but something keeps telling me it is something else, so I thought I would check here and it looks like others are having the same problem. Any input would be greatly appreciated.

[fastrnu2]

What plugs are you running, sdi 's need the br9ecs not the br9ecs5

[Shrek607]

What plugs are you running, sdi 's need the br9ecs not the br9ecs5

I am running the BR9ECS

[02GTSE]

I would try seafoam as robinap suggested. It sounds like it is lean popping, possibly due to the increased air flow with the vforce reeds and injectors might be a little dirty causing a slight lean condition.

[mbret2004]

well today we were working on it and i did check the sensor in the muffler and it read 199 oms ... when we unpluged that muffler sensor it still poped but not as bad and it seemed to run a bit better but still popping.road it for about 1/2 hr so it got good and hot and ran fine but it was just popping..it did eat the pull rope side plug (and has ate that side a couple times over last season and this season)

i dont know what else to do...the fuses look clean ...i have moved the resistors around...i thought maybe that o2 sensor in the pipe mite be it since the reading was lower then 220oms????

remember temperature affects resistance, the doo sensors have a negative temperature coefficient ( NTC) In English, this means as temperature increases, resistance decreases, the inverse is also true. A 20% correction factor is a rule of thumb if you're not working in an area where the room temperature isn't 68F. Normally, resistance numbers assume you're working at room temp--that would be nice.

So, since you read 199-ohms and 220-ohms is what's called for, your correction factor is 220 [+ or - 20%)] so your resistance reading should be between 176 and 264 ohms. Your sensor is within limits BUT it can still be malfunctioning. This "static test" doesn't tell you if the sensor reacts properly with varying exhaust temperatures. At this point you might want to see about getting it hooked to the BUDDS system. How much are the sensors?

[robinap]

sdi exhaust probe is only to there to tell engine if extreme hot condition occurs and does not effect mapping.