car stumbles to 4500 rpm's then goes like ....

[KJYERM]

i've been pulling my hair out trying to figure this out . i would'nt say it misfires but it feels like a very small boost leak but when the rpm's hit 4500 it goes the way it should . i have a 16g 'walbro 190 and 3" full exhaust. I had another turbo and manifold set-up on this engine, I even had another engine that it did the same thing. It has got to be something with a sensor or solenoid or some boost leak that I am not finding. It seems that I can't hold steady boost, but none of my lines are leaking. Could it be leaking in the engine somewhere. But it is pretty consistent at 4500 rpm's. Hope that is a little bit better information. Thanks.

 

[TwoLiterLaser]

Your profile needs to be updated. Other than the 16g and walbro 190, what is in your car? A 420a with only a 16g and a walbro 190 will not run correctly. And what do you mean by 3" exhaust to the O2 housing? The O2 housing should be part of the 16g.

 

[KJYERM]

i don't know how that happened to my profile but it was pretty much wrong. its right now. thanks and i have 3" full exhaust

 

[Turboeagletalon]

sounds like your wastegate solinoid is sticking open, or the electronic solinoid is.

 

[TwoLiterLaser]

I am not saying it is not a sensor crapping out on you, but what boost are you running? And I am correct in saying that you are using stock injectors, MAF, and no fuel management right?

 

[2ez4me]

if its just breaking up like it stutters at 4500..change ## sparkplugs and wires...My car was doing the same thing at 4700 when i pushed it hard and it went up but slow and jumped..was very frustrating

 

[KJYERM]

running 16 psi yes stock maf tried plugs/wires .gonna take it to High psi. keep you guys posted thanks for your help