my wife has a built d16z6 (by me). I was tuned at speed factory a year ago and it has ran great @ 307 whp. This last week we have noticed some cutting out at part throttle so I checked the plugs and show a lot more white than before. I raised the fuel pressure from 40psi to 60psi, the plugs are not as white, but why the change? have good vacuum, and no exhaust leaks. help please

 

help :/

 

What's the plug gap at? Sounds like its opened up on you.

 

changed the plugs, the gap is at 30. I guess I could put another set in but i don't think that is the problem. It just started to run lean one day. it seems to be consistent thou.

 

Last time u changed the fuel filter?
Slightly clogged injectors?
Fuel pump getting old losing some flow?
Just throwing out ideas

 

All the cylinders are burning the same so I don't think clogging is the issue. Pinched off the return line, it built and held high pressure with the new 255. ordered a new fuel filter because that's the only thing I can think of. I think we are thinking in the right direction tho, thanks for the thoughts