viper mtx turbo sputter after holding it open for a bit

[madsledder]

First ride on my viper after I put a power commander on. Got commander used with ulmer tune in it. Way snappier than the gems. At 6 psi it sputters after I hold it open for a bit. So I tried 5 psi same thing. topped up oil thinking it was the oil light same thing. Sounds like its hitting rev limiter about three times (it's not) then it runs crappy for a little bit 10 seconds or so. Then runs great till I hold it open for about 10 seconds again. Sure its something simple. Tried Ulmer but he's a busy man so any one have a map I can compare mine to for up to 6.5 psi max and high flow exhaust and intercooler? MPI base kit Thanks.

 

[mbarryracing]

Do you have a AFR gauge?

 

[madsledder]

No I went to put The koso I had on and can’t find the sensor. Talked to Ulmer gonna add a bit of fuel see what it does and find a pod 300 and auto tune. Or at least get a sensor.

 

[mbarryracing]

Fresh fuel? I wouldn't be horsing it like that with a new-to-you fuel box program without an AFR gauge... could be too lean and flirting with detonation.
You gotta know what the A/F ratio is...

 

[madsledder]

Ya fuel was fresh. Maybe I should drain it and refill. Also I ordered a auto tune and a pod 300 so next ride no guessing.

 

[madsledder]

Been a while since I looked at a a a/fr guage. What numbers do I set the auto tune to? If I remember right 13.0 10% up to 30% then 12 up to 65% and 11.5 for the rest?

 

[ClutchMaster]

Try a new set of plugs.

 

[ClutchMaster]

You can run 14.5 afr for most of the off boost area of the map. At 70 load start richening up 13 afr. When you start getting into boost lots of guys like to go really fat on the mixture as this will help spool the turbo around 11:1 afr. Hold it as close to 11:1 as you can up to 200 load.

 

[Riceburner]

Been a while since I looked at a a a/fr guage. What numbers do I set the auto tune to? If I remember right 13.0 10% up to 30% then 12 up to 65% and 11.5 for the rest?

That should be fine. Could go a little lower up top for an extra margin of safety.

 

[ClutchMaster]

Is 100% set up to be zero boost (0-100 vacuum, 100-200 boost) 200% = 14.6 psi boost? If so your mileage will suffer with those settings.

 

[ClutchMaster]

It’s not like throttle position tuning for a N/A viper, the turbo power commander uses a map sensor for pressure based tuning.

 

[madsledder]

What would cause a sled to lean as you go up in elevation?

 

[Riceburner]

What would cause a sled to lean as you go up in elevation?

Generally, It shouldn't, it should go rich.
Air is less dense at elevation.
Unless the temperature drop at elevation causing more denseness exceeds the lean effect caused buy the elevation increase.

 

[ClutchMaster]

Used power commander? Unverified tune? No AFR gauge? Dude your taking a lot of chances you’ll be lucky not to blow your motor up.
You said it runs like crap for 10 seconds after sputtering, well that’s a fouled plug.

 

[madsledder]

No power commander has the right tune verified that. Auto tune with pod 300 is what I’m looking at. Thinking there might be an issue with something electrical on the sled screwing with stuff. Not sure what could do it though. Put new plugs in it maybe one had bad ceramic causing it like the old m’s and non resister plugs and a boondocket box.