08 T dragon 800 help

[jskattum606]

I have a 08 800 dragon motor in my project sled that is having some fueling problems. The fueling seams to fade in high demand situations. Just so you know the set up, It has a Dobeck box on it, i run it at 10 PSI running strait AV gas with a 2871 garrett, have ran from 30-45 fuel pressure at idle, and i have a A/F gauge on it for tunning. The problem seemed to have started after a hard wreck.
It gets so lean that it lean pops and i have blown out the reeds. The first few pulls of the day, I can stay on it WOT for at least 10 seconds and after then It just takes a second to go lean. Half throttle and below it will run flawlesy. I can run it all the way down to 10.5 A/F at WOT and it will still go lean after a few seconds.
Here is what i have done so far.
New fuel filter
Changed the fuel pressure all over the place.
Swapped the Fuel controller box out
Checked the injectors
Checked the voltage to the system( at about 13.5V at idle)

If any one has any ideas or has ran into this before i would appriciate the help.
Next thing im gonna try is putting my FPR gauge in a visible spot so i can watch it while it is acting up to see if it is fluctuating. Also i think im gonna swap out the fuel pump because i have an extra. It is a summit pump by the way, Not the in tank poo pump.
I feel like it may be an electrical issue(ECU or VR) so any help in testing these thing would be great.

 

[KAWGRN]

can you see the guage on your rrfpr to see if your pressure is rising as you build boost??

 

[Spaarky]

What are you using for a fuel tank? We had some problems with the fuel return on mine, there was a seal or washer that was causing fits. I can see my fuel pressure from the cockpit, and it was making it do wacky things. We just removed it and it has been fine since.

 

[bighole1818]

Fuel filter?

I didn't see on your list if you had changed the fuel filter or not. had the same problem on an 09 dragon, started like yours then steadily got worse untell it would hardly run. Replaced the filtler, ran great.

 

[jskattum606]

can you see the guage on your rrfpr to see if your pressure is rising as you build boost??

This is the next thing im am going to do for sure. Should give me a lot more info.

What are you using for a fuel tank? We had some problems with the fuel return on mine, there was a seal or washer that was causing fits. I can see my fuel pressure from the cockpit, and it was making it do wacky things. We just removed it and it has been fine since.

Was it restricting the flow? Where was the seal or washer? On the FPR
I am running a Skidoo rev Tank With the dual polaris fuel pickups in the tank and the fuel return plumbed into the top of the tank next to the tank vent hose.

I didn't see on your list if you had changed the fuel filter or not. had the same problem on an 09 dragon, started like yours then steadily got worse untell it would hardly run. Replaced the filtler, ran great.

Yep, This was the first thing i did. Didnt change the problem at all

 

[jskattum606]

Also put some new throttle body boots on the other day just for maint.

 

[swrev]

With my turbo xp, mine is doing something similiar right now, couldn't tune the the thing in for the life of me until I added some more fuel. I believe I am having a problem w/ my fuel pickup in the tank. I could see air going through the fuel line. Maybe your Rev tank is doing something similiar. Never been in the tank before, so I don't have any idea what is inside.

 

[jskattum606]

With my turbo xp, mine is doing something similiar right now, couldn't tune the the thing in for the life of me until I added some more fuel. I believe I am having a problem w/ my fuel pickup in the tank. I could see air going through the fuel line. Maybe your Rev tank is doing something similiar. Never been in the tank before, so I don't have any idea what is inside.

Yep, already been though this. I endded up putting Dual EFI pickup screens in the tank. One in the front and one in the back. Ran great after this and the i had a hard impact that caused this problem i think.
Bacically, The carbed skidoo tanks have just a tube that hangs back in the tank about 2/3 the way to the back of the tank on the bottom. When the fuel sloshes after about 1/2 full, the fuel pump sucks air. Not a big deal with carbs because they have float bowls. But with EFI the rail looses pressure.

 

[swrev]

Thanks, what EFI pickups did you use? Cat or Polaris? Hope you get the sled figured out. When I watched the vids of it running, I warned the wife that I might have to throw you an offer and try to buy that sled.

 

[Wheel House Motorsports]

hmmmm... i just had a smart idea after thinking about your accident... once your done getting your back un busted were gonna go fix it up.. using my brain right now and i think i got it dailed.. and if im right on this one, you WILL laugh at it.

you have dual pickups.... you wrecked VERY hard nose down, you also never fill your fuel tank all the way up as it leaks.. the pickups could be both slid to the front of the tank and gotten stuck. it iwll run alright in the morning because you still have reasonable fuel levels, but once you suck it down any, your already lower... and when your WOT your tank is generally speaking angled back QUITE a bit.

 

[jskattum606]

Thanks, what EFI pickups did you use? Cat or Polaris? Hope you get the sled figured out. When I watched the vids of it running, I warned the wife that I might have to throw you an offer and try to buy that sled.

I used the ones out of a polaris. They work great. You can also just buy them seperatly here
http://www.autoperformanceengineering.com/html/pickups.html
They will keep sucking fuel till the last drop

 

[Spaarky]

It was a IQ tank. It was in the return elbow area. If I remember right, it put the fuel pressure through the roof, but sled would not run right. It was a couple years ago.

 

[Eli]

I had my rear in-tank fuel pickup twist 180 degrees and give me symptoms similar to yours. When I got near a half tank, the sled would want to die idling going down steep areas, and would go lean climbing pretty vertical. I pulled the pump, straightened the pickup assembly and could do long pulls on reserve after that. Maybe check that....it's simple to do.

 

[Wheel House Motorsports]

i think your sled is gay.... thats really the only logical thing left for it to be.

now with the new fuel pump, different regulator and fp gauge where you can see it while riding, we can do some diagnostics..

 

[jskattum606]

It was a IQ tank. It was in the return elbow area. If I remember right, it put the fuel pressure through the roof, but sled would not run right. It was a couple years ago.

Good to know. Thanks for sharing your experience. Noe that my FPR is in a visible spot, I can field test it a little better.

I had my rear in-tank fuel pickup twist 180 degrees and give me symptoms similar to yours. When I got near a half tank, the sled would want to die idling going down steep areas, and would go lean climbing pretty vertical. I pulled the pump, straightened the pickup assembly and could do long pulls on reserve after that. Maybe check that....it's simple to do.

This is what mine was doing with the stock skidoo tank set up. I did put the pickups in right but thats not to say they could have moved. Great idea. Ill have to check it out. The rear one is hard for me to see thought as i do not have a removable plate to check everything out. Luckily the tank is kinda clear.

i think your sled is gay.... thats really the only logical thing left for it to be.

now with the new fuel pump, different regulator and fp gauge where you can see it while riding, we can do some diagnostics..

Thats gotta be it. I hope it gets its act together.

 

[Wheel House Motorsports]

Thats gotta be it. I hope it gets its act together.

Gonna have to sit it down with a hammer and give it "the talk"... you know what it is.

hopefully the awsome new lightweight fuel system fixes it.. with the ninja return line.