Mcx 270 stumble

[Nitram]

hey guys still trying to figure out my stumble on my 08 mtx nytro with mcx 270 turbo. At idle it will fluctuate up and down. Not really a rough idle. But if I rev it up a bit just enough that the sled won’t move it runs horrible. Really rough and like a pretty bad miss. Could it be a boost leak? Secondary injectors? I installed a brand new set of plugs and didn’t change anything. Top end power still seems to be there and no stumble or miss. Also seems to hesitate for a quick second as I give it more throttle. Any help is greatly appreciated fellas. Thank you!! Cheers!!

 

[M7000]

Im having a similar issue with my mcx 190 kit on my M7000. When doing high rpm it works great, but when driving really slow, the rpm will flicker even though im keeping the same throttle position.

I know on my sled there is some exhaust leaking between the muffler and turbo, because mcx doesnt use a gasket there. And since im not running a snorkle kit, the turbo could be sucking in exhaust and causing the rpm to flicker when idling/driving very slow.

Another detail is the battery might be a bit low, since when i was installing the turbi i had some issues with vacuum hoses connected wrong - and thus had to try many start-ups.

First im going to adress the exhaust leak to see if that is causing the problem.

 

[mbarryracing]

Do you have an AFR gauge? What is the AFR doing when it's stumbling at a high idle below engagement?
Does MCX use an TPS signal? Wonder if that is screwy.

 

[Nitram]

Im having a similar issue with my mcx 190 kit on my M7000. When doing high rpm it works great, but when driving really slow, the rpm will flicker even though im keeping the same throttle position.

I know on my sled there is some exhaust leaking between the muffler and turbo, because mcx doesnt use a gasket there. And since im not running a snorkle kit, the turbo could be sucking in exhaust and causing the rpm to flicker when idling/driving very slow.

Another detail is the battery might be a bit low, since when i was installing the turbi i had some issues with vacuum hoses connected wrong - and thus had to try many start-ups.

First im going to adress the exhaust leak to see if that is causing the problem.

I just ordered an exhaust flex pipe and fixed a couple of boost leaks. Next I will check the secondary injectors in the intake plenum to see if they are leaking

 

[Nitram]

I

Do you haver an AFR gauge? What is the AFR doing when it's stumbling at a high idle below engagement?

ahh crap I don’t have an afr gauge. Been on my to do list to get one

 

[M7000]

D

I just ordered an exhaust flex pipe and fixed a couple of boost leaks. Next I will check the secondary injectors in the intake plenum to see if they are leaking

did you figure out anything yet? I havent gotten around to adressing my issues yet. Been cold af up here

 

[Nitram]

D

did you figure out anything yet? I havent gotten around to adressing my issues yet. Been cold af up here

Not yet bud. Just picked up my exhaust parts yesterday. Took forever to get here. Gonna get it back together tonight and try it. Once I get the exhaust back together and the tank back on I’m gonna run it with the secondary injectors out and see if they are leaking. Kinda thinking that’s the issue. Will keep you posted!!

 

[Nitram]

Boost leaks fixed. New exhaust flex pipe installed and still no improvement. Seems to only get bad once the sled warms up. I’m lost. Added a video. I really hope someone can help

 

[M7000]

Tried fixing my exhaust leak with some heat bandage stuff between the muffler and the turbo. Im not noticing that much rpm fluctuation while driving now.

But what i do notice is that when im driving and if i let go of the throttle, the rpm will drop all the way to 1100rpm. Wonder what it is doing that?

 

[M7000]

Figured out the bogging when letting go of the throttle. I tightened the drive belt. Apparantly if your belt is too slack it can cause bogging.