so i recently helped my friend turbo his d16 with a supra ct26 turbo. We are having major fuel/spark issues and i have some questions about it. First he went one step colder with the plugs over stock and gap to .038. We recently put in DSM 450CC injectors with a resitor box but it seems as tho the car is flooding itself out at idle. It will drive fine untill boost starts to build and then its almost like a extremely bad missfire. Could it b that the fuel is blowing out the spark? Plz help thank you.

 

sorry d16z6 sohc vtec 1.6

 

Search then tune.

 

I'm guessing that...

1) you are running the stock ecu, meant for 240cc injectors
2) are running a stock fuel pressure regulator, and no FMU
3) have no real clue about forced induction, ignition, etc


1) You 'simplistic' MAP-based ecu makes fuel corrections at partial throttle to a certain extent - 320cc injectors are considered the biggest you can use to idle on a stock bin. WOT is where you have the issues - your ecu reads directly from the fuel maps, meaning it is HIGHLY LIKELY to be very far off from an ideal AFR.

2) no fmu and no ecu tuning with a map-based setup is just dumb. even the primitive afc hack is better.

3) WOT is rougly 14.7psi [above absolute vacuum] at sea level, normally less due to elevation. When you add 6-10psi (differential, ie 6-10 above outside atmosphere) with a turbo (~14+~7=~21, 50% more air), you have a air/fuel mixture roughly 1.5 times more dense. In a typical turbo'd combustion chamber you need a richer mixture than usual, meaning its about 1.5-2 times harder for a spark to jump across the plug. That means your two options are - double the power sent through the plug or reduce the gap by one half. Guess which one is easiest...