Turbo nytro cutting out at WOT...

[Turbo_everything]

First off hello everyone as this is my first post.
Here is the issue, sled runs strong at 1/2-3/4 throttle but if I go to full it will cut out. Rolling to 3/4 then punching it to wot will cut out right away. Going wot from a stop it will go for a few seconds till hits around 5# then cut out. Feels like a rev limiter but it's not. I've been chasing that for a while, I've got it running at 8300 ish till I figure this out.
Set up. Custom turbo built by me. Gt2560r turbo running at 7#, tail bov, aeromotive fuel pump and return reg running at 41#, custom tank with 2 stages to prevent starving, small fuel pump to fill second tank. New stock plugs gaped at 24 (could be issue trying this weekend at 19), pc5 with auto tune and 3 bar sensor, running 11.2 afr at full boost 3/4 throttle.
Any help will be great! I'll be calling ulmers after holidays because that's where I got the pc5 and see if he can help me out.
Thanks

 

[Turbo_everything]

Just to let everyone know, so after tying to find every electrical issue on a nytro and making differnt maps for it (lean and rich) I've found the issue. The stock injectors where cutting out at boost. Not sure why they where, I had a feeling after watching the afr and after one run I saw it spike to 15 for a quarter second then drop back to 10.5. So I figure they where cutting out long enough to drop boost then turn back on and go rich. So I went to 430's and a new map for them. Runs great now

 

[ghost rider]

Good to know.... I have the same problem but with a carb engine..... It's still a mystery.

 

[Agman 57]

Sorry but I'm missing something. Is 430's a bigger injector? Did you put in new plugs and narrowing up the spark plug gap to 19 do anything for you?

 

[ghost rider]

Plugs at 19 I use takai iridium plugs.... Helped some but mine still cuts out at wot once warmed up
Carbs have been re jetted for AFR of 11

 

[Turbo_everything]

Hey sorry for taking so long, I've been out of town. Yes 430 are bigger, stock are 330's I belive. I Tried the plugs first. When I first started testing I made the oil return to small so the turbo leaked some oil into the intake and caused my plugs to fail and the nytro would not start. I had them gaped at 22, then gaped them to 19. It did not seem to do anything. But I know that's where they should be for a turbo. I'm using stock plugs. I could go on forever taking about what I've tried and tested. I think the stock injectors where lower flowing then what they should be so they where maxing out. since no injector really flows the same, that's why they sell them in sets to match them as closely as possible. If that wasn't the issue I was going to set her up on a dyno to find the issue. But now she is running at 99% I've dialed the map in just running a tad rich but I'll take that over to lean and burning the motor down. As for your carb turbo they can be a pain in the a** because of the fuel adjustments compared to a FI set up. The issue could be anything. I would guess fuel is running out. Do you have a afr gauge and boost gauge? If not that's the first thing I would do and check your afr. Find a long flat stretch and slowly roll into it until WOT. I like to run afr: 13.5 at idle, 12.5 cruising and 10.9-11.2 at wot. Any leaner at wot and will burn the motor down I've seen it lots. As for cutting out I would check fuel flow, do you have a larger fuel pump? Maybe the bowls are going dry at wot. I would also throw it on a dyno to check since you can't just pull up a map like I can and check to see what it's trying to do for fuel adjustments. Even then I've learned that your ears can be some of the best tools. Listen for lean pops and rich gurgles. I find if it runs really strong then dies a bit then pops or farts or cuts right out its too lean. If it runs ok but seems to bog a tad and has weird gurgles its to rich. With mine it had a mid rpm gurgle at wot until full boost. Had to lean it out to get the rpm tone to be seamless. That's what I shoot for is a constant rpm tone from low to full rpm. I could go on and on with opinions lol. But opinions are like a**holes everyone has one hahaha.

 

[ghost rider]

Awesome info thank you... I run the same afr's on mine but get the cut out stumble, burble and sut down
Until I re start and then runs fine.... Until I hit the throttle.... The longer I ride the worse it gets.
I have been chasing this demon for two years..... Added bov, re jetted to 126. Afr is within spec just as you stated.
I don't have black carb springs yet.... Fuel pressure is solid at 5 psi (carb) Plugs are new gap at .19
Boost at 10 lbs stock engine no shim... Run 100 octane..billet carb caps. Original electronics ie) stator and ecu
New coils but stock.
I have run out of ideas and have more than likely drove a few members crazy with this problem.

 

[Turbo_everything]

So just a few questions, now does the seld shut down at same throttle position and boost every time? Have you checked for a vacume leak? How much boost are you running?

 

[ghost rider]

10 lbs boost no shim, race gas 100 octane Checked for vac leak... Nothing I can spot however
I'm a supercharged, fuel injected car guy so the Sled motors are a bit of a mystery with all those tiny parts.
Never a dull moment .... But I need to fix the shut down at wot as it's very annoying now... Last season it was interesting
Now I'm going insane.......all systems are normal.... In theory and by measure...... I'm starting to think electrical
As its not in my fortay of mechanical specialties...... I just don't know.....its a real SOB.

 

[Colorado Nytro]

We chased a similar problem and found it to be the wiring harness rub was cutting out a injector. Inspect the harness down low by the clutches, it took a year to find this issue.

 

[Kurilchanin]

Hi guys!
Can you tell me that over 430 cс injectors that you manage?
I want to install large injectors but none where I can not find information that will work well with the 10-12 Psi boost.
I will be glad for your help.

 

[Yamadog]

10 lbs boost no shim, race gas 100 octane Checked for vac leak... Nothing I can spot however
I'm a supercharged, fuel injected car guy so the Sled motors are a bit of a mystery with all those tiny parts.
Never a dull moment .... But I need to fix the shut down at wot as it's very annoying now... Last season it was interesting
Now I'm going insane.......all systems are normal.... In theory and by measure...... I'm starting to think electrical
As its not in my fortay of mechanical specialties...... I just don't know.....its a real SOB.

I had a 03 RX mountain that I bought with a Bender rear mount turbo on it. I worked on that thing for 2 yrs and then gave up. it did the same type of thing. Jetted carbs are so hard to set up. If your jetted correctly for 3000 ft at 10 deg f with 100 octane any change would affect it. I ran around with a complete jet kit and would have to change the carb jets 2 or 3 times and then the jet in the charge tube in a weekend. Mine would either run good from low to mid range or just on the top and would stumble and burble to get it WOT.

Now a days with injection - the new viper or nitro or Apex makes it so easy to boost them. (if you have a big wallet) but my viper now is at 13#'s and 252 hp and runs like a volkswagon.

 

[Turbo_everything]

Awesome info thank you... I run the same afr's on mine but get the cut out stumble, burble and sut down
Until I re start and then runs fine.... Until I hit the throttle.... The longer I ride the worse it gets.
I have been chasing this demon for two years..... Added bov, re jetted to 126. Afr is within spec just as you stated.
I don't have black carb springs yet.... Fuel pressure is solid at 5 psi (carb) Plugs are new gap at .19
Boost at 10 lbs stock engine no shim... Run 100 octane..billet carb caps. Original electronics ie) stator and ecu
New coils but stock.
I have run out of ideas and have more than likely drove a few members crazy with this problem.

I here you on this. I’ve been thinking about this for a while but can’t think of much else you haven’t tried. As for what Yamadog said, I agree and the jetting is a huge pain in the a**. Have you ever thought about putting an EFI from a later sled on? I would think most of the harness; TB's, rails and etc would cross over. Might be opening a bigger can of worms but just a thought. Have you tried the black spring yet? The other thing I thought of is do you have a 1:1 rising rate fuel regulator with a return? Running 1:1 (fuel psi to intake psi) on top of your 5 psi, 15 psi at 10 pounds of boost might help it keep the bowls up.

 

[Turbo_everything]

Hi guys!
Can you tell me that over 430 cс injectors that you manage?
I want to install large injectors but none where I can not find information that will work well with the 10-12 Psi boost.
I will be glad for your help.

I got mine from a dealer, he had them lying around from an old turbo kit. I would try Hurricane performance in Canada, I know that the use 430cc as well. Or you can go with a boost it set up, I know allot of people are happy with them.

 

[Kurilchanin]

I got mine from a dealer, he had them lying around from an old turbo kit. I would try Hurricane performance in Canada, I know that the use 430cc as well. Or you can go with a boost it set up, I know allot of people are happy with them.

Hi!
I do not understand a bit, I'm from Russia and poorly understand English. You may ask where these injectors 430cc. And how much they cost. Maybe I would have bought them.
I really need your help. Thanks.
You can write me a mail vgichen@mail.ru