need a bet of help

[mulot30th]

The ecm?

 

[Blue shadow]

I change that to from another sled mulot.Still the same .Rx rider there is nothing in the exhaust side but the colour .It is very black ,even the exhaust A/F sencer is cold black.

 

[Blue shadow]

What haven't you checked?

the only thing I did not change was the stator plate but it reads ok when I take a reading .

 

[lakercr]

Sounds like your carbs are not seeing the correct vacuum/pressure signal. Are you running STM caps?

Focus for a minute on everything from the IC pitot>float vents>T's>caps/springs.

First thing I would do is pop the caps off and make sure everything is in order.

 

[rx1 fern]

hi jim ,nice to see your back.good to see.

 

[Blue shadow]

Got all that covered Jim ,I even put my carbs on another sled and its ok .

 

[Blue shadow]

Going to start all over again and see if I miss something.

 

[Blue shadow]

I made some headway today .I recheck everything and it still does the same .I remove the turbo and took it apart and all is ok .I did not remove the exhaust .Tryed it again and still the same .So I left the wastgate open this time and she runs fine from 0 to 10000 rpm with out no hesitation .NO backfiring at all ,just like she all ways was .So I close the wasgate again and the same thing happends again at 4000 rpm she backfires and dies again.With it open she runs perfect.What in the name could be causing this ?thanks

 

[HURRICANE]

check the exhaust turbine for a mouse nest

 

[Ted Jannetty]

I made some headway today .I recheck everything and it still does the same .I remove the turbo and took it apart and all is ok .I did not remove the exhaust .Tryed it again and still the same .So I left the wastgate open this time and she runs fine from 0 to 10000 rpm with out no hesitation .NO backfiring at all ,just like she all ways was .So I close the wasgate again and the same thing happends again at 4000 rpm she backfires and dies again.With it open she runs perfect.What in the name could be causing this ?thanks

That is the problem with Wide bands, when the engine misfires the gauge will show lean which then sends you down the road chasing a lean condition which I doubt you have.

Remember Oxygen Sensors Don't Measure Fuel, they Measure Oxygen content only.

You should be chasing a misfire, here are some Ideas, Bad battery, grounds, bad fuel is a big one, an overly rich transition can cause this also.

I don't know if you installed the clutch yet but you should not be doing any testing without a clutch and belt in place.

 

[Blue shadow]

New battery ,all grounds are clean good,new fuel, she ran fine last year with the 153.8 main jetting.She does the same with the belt on .

 

[Ted Jannetty]

New battery ,all grounds are clean good,new fuel, she ran fine last year with the 153.8 main jetting.She does the same with the belt on .

I have never run that big of main Jets.

Could be crossed signal hoses for the float bowls VS Pressure Regulator.

Are you seeing Fuel Pressure rise with Boost?

I don't know what your using for signal hoses or fuel hoses but I have seen the inner liner of fuel hose collapse, you may want to check all your lines both fuel and boost signal.

 

[Blue shadow]

Ted We don t have snow yet ,this is only on a stand.I put all new hoses on .Float bolws and pressure regulator hoses are in the right place.Last year with the 153.8 mains on 22 psi the A/F was 11.8 at wot.Why would It run good with the wastgate left open on the stand.When I close it again she back fires at 40000 rpm .Open the wast gate again and its fine.Just don t make sence.

 

[Sibola]

Like Hurricane Dave said start looking for a mouse nest, bet some where in the turbo or exhaust.

 

[Blue shadow]

nothing ,I check .thanks