so y buddy has a z31 n/a to turbo conversion (vg30e) and is having a little bit off a problem with it. it runs and idles fine... but when he gives it gas it goes up quick to about 3k and then starts bogging down. its been doing this since he started messing with it so we went through and replaced a few things.. at first it seemed to be a fuel problem so he went out and got a walboro 255lp and new 440cc injectors.. installed them and is still having the same problem. we also change the mass air flow and nothing has changed.. just running out of ideas of what it could be.. but it really only seems to do it when it hits boost.

any tips are helpful thanks

 

also its obviously running rich.. but would that cause it to bog down at higher rpms?...

 

What ecu / tune is he running to accept 440cc injectors?

 

just a stock turbo ecu

 

The stock ecu cannot compensate for larger injectors... especially ones dumping DOUBLE the fuel...

Put the stock injectors back in, and check the ecu codes.

 

what boost are you running? what is the fuel pressure? Some info besides it doesn't run might be helpful

 

7lbs of boost... on a stock turbo and 37 for fuel pressure.. we were thinking we may have to actually replace the fuel pressure regulator.. could it be clogged? and would it cause it to bog like that.. im knew to z cars so i dont know alot about how they tick as much.

 

we ran a diagnostics and we got a read for the chts.. aswell.

 

the ecu codes are seldom helpful but in the case of the CHTS just replace it. Did you run a line from the manifold to the FPR. the pressure on the fuel ring should rise with increased boost. My 86 T has 20 psi at 20 in HG. It rises to approximately 44 in full boost of 10 psi. and yes the injectors are way to big for your setup. You can't just slap parts on something without a basic knowledge of how the system works. you did I hope check for vacuum leaks which are the bane of the FI engine.

 

Well there's your first problem....