09 M8 SP Hard start, major bogging. Unrideable.

[Bauer]

It's just weird. Never had a single problem with this sled, until recently. Fresh top end this fall.(2200 miles on it,139 hrs) 2 rides, ran like a champ! Then the clutch started hanging up. New primary, ran like a champ! Started it to back it off the trailer and it died. After some tinkering found out that the fuel pump had seized. Got new pump. Not from Cat, because if they think i'm going to pay $670 for a pump they need drug tested like, now!

So the new pump was pumping but it still wouldn't start. Stuck injectors? Yep. Took a 9v to them and she fired right up. Put everything back together, started it again, all fine.

That was last Saturday, today, went out to fire her up and it would stumble around 1000 rpm then die, this happened about 6 times then it would come to life like nothing was wrong. Loaded it up and headed out.

Got up to the parking area and it wouldn't start. (home 5k feet, parking area 8k feet) Finally got it to fire, rode it around and it would get to 6k rpm then bog almost to stalling, then go back to idle. This happened every time. Then finally had to be loaded back up. Got home and it did the 6 time pull and then fine thing, rode it off the trailer and backed it into the garage. Idled fine, revved fine, nothing seemed wrong. I'm not even sure where to start. Any ideas? Everything is still connected and stock, except for the RKT head.

 

[Sledbrain2]

I had an 02 800 that had similar issues, I had to cycle the injectors to get it to start and idle, Once running it would run erratically, I would hold a steady throttle and it would surge(accelerate and decelerate) to the point you could not ride it. Turns out it was a tps, Should be able to do test with homemade tester. Just need an old phone charging usb cable, You need 5 volts and that is what a phone chargers uses, cut the usb cable find the black and red and soldier to a couple leads, they are too small to use a crimping connection. Then you need a volt meter, I made my own with alligator connectors. On the tps black/dark blue is neg, white is signal, and red is positive. self explanatory from here, apply 5 volts to black and red and place the volt meter red to signal. You will have to find the minimum and maximum volts from idle to wot, If the tps reads steady then its probably not the issue, if it does not stabilize then you found your problem. For instance a m1000 has .59 to .69 idle and 3.47 to 4.05, When I was setting mine when I worked the throttle it would stabilize if I held the throttle still.

 

[Sledbrain2]

Also note that to get to throttle body is a pita, you have to pull the intake, oil injection lever and the coolant lines to get throttle body where you can test it. The other option is to remove the oil tank, from what I have read both are a major pain in the a$$.

 

[Thunder101]

any chance you could have water in your tank ? Do you store it out side ? have you rode it at all this season before the problems ?

 

[Bauer]

I don't think water is a possibility, the sled and gas are stored in a heated garage. And yes, I've been riding all season. The day the pump went out it probably ran better than it ever has. Now it's being all weird and quirky. I'm going to be checking the fuel pressure, TSS and a few other things when I get a chance. It's just weird to me that it happened all at once, and why did it happen all at once.

 

[Readymedic]

It doesn't matter if your sled is in a warm building or garage. The gas tank must be full of gas when it sits in there, or you will get a lot of condensation(water) in your tank. FYI...

 

[kiliki]

Start with the throttle safety switch they are a pos.

 

[Bauer]

It doesn't matter if your sled is in a warm building or garage. The gas tank must be full of gas when it sits in there, or you will get a lot of condensation(water) in your tank. FYI...

There is that. It was empty when I was messing with the pump. But it gets more fun. Just went and started it just to see if it may trip any codes. Started 3rd pull and ran fine.

 

[Bauer]

Start with the throttle safety switch they are a pos.

That's next. Need to go buy a smaller torx set to get the throttle apart.

 

[Frostbite]

My 09 M8 is doing the same thing. It ran great, then it wouldn't start and now it starts fine when cold but, won't restart sometime wen out riding. I have that weird 1,000 RPM idle that fades off to nothing..........and the sled dies.

I have checked ground wire and updated the firmware on my PCV but, haven't tried the sled since. I wish you luck! let us know what you find please.

 

[Bauer]

Well. Tested the fuel pressure tonight with a Harbor Freight kit. (cut me some slack, wife works there and it didn't cost me much) Anyway, it was only reading ~15psi. It fired right up and ran and revved fine. Got the pump from Flip MFG. Either the pump is junk or the HF gauge is. And the 1000 RMP to death, has gone away. Will these things even idle at 15psi?

 

[Frostbite]

I got my fuel injection pressure kit from Ebay for $20.00 with free shipping so I am no better but, I haven't tested the fuel pressure yet.

 

[Jughead2]

TPS or maybe a reed.

 

[lips3469]

Mine did kind of the same thing it turned out to be oil rod sticking it would get hung up. U can see it hang up when play with the throttle. All I did is tweaked the lever (not the rod itself) worked just fine. But when u do that it messes with rpms so little adjusting my be needed.

 

[Frostbite]

LIPS, do you mean oil rod connected to the oil pump? I remember there was a mod to add a stronger spring to the oil pump to make sure it re-sets properly.

 

[Bauer]

Still not much luck, everything that can be tested has been. Does anyone know what the amp draw on a stock AC fuel pump is? The Flip Mfg pump is drawing 5-6.8 amps. Voltage to it is 17 volts unloaded and 8 volts loaded. At this point the guess is the aftermarket pump doesn't jive with it, or the ecu is hosed.

 

[Bauer]

Figured it out, I hope. Cuz I already ordered an AC fuel pump. The Flip pump draws 5-7ish amps, the AC pump only draws 1.5-2 amps. Hope to be back on the snow next weekend.

From what I understand the Flip pump may work on sleds with batteries that help make up the difference. Kind of a bummer $50 is a pretty sweet deal compared to $600-$800. O well.