2G Engine sputtering/hesitation under hard acceleration with high boost

[Brad Bell]

Just got my 1999 eclipse 420a turbo running and it seems to sputter or missfire very bad under really hard acceleration, most cases with my max boost of 8psi. If I ease into the acceleration slowly it never happens, however when I quickly floor it to WOT it sputters very badly. I checked the spark plug gaps and they are at .028in. possibly it is my coil pack or wires.

I have a rising rate fuel pressure regulator along with a walbro 255. Under the 8psi of boost I am reaching around 95psi of fuel pressure. It is what my manual calls recommends for my turbo kit. Hahn racecraft stage 2. Not sure what is happening, runs great at normal acceleration and idle. Thanks for all the responses!

 

[PlanZero]

Boost leak test.

 

[Brad Bell]

Boost leak test.

How can I do one?

 

[SasaniFab]

How can I do one?

The first thing you need to do is install a wideband o2 sensor, if you dont have one already. This is a fmu your referring too? Its very possible your running your engine rich. The only way to know that is with a wideband. Your blind otherwise. You need to do some searching in regards to boost leak testing. Its a very simple procedure and you shouldnt be driving around until you can verify that your system is sealing properly.

 

[Talonman86096]

Should get a wideband for sure to monitor your fuel mixture, but also try replacing the spark plug wires if you haven't done so. I've had similar issues when I needed new wires. Fairly cheap to replace and takes only minutes. Pop the hood at night and look at the wires while the car is running, sometimes you can see sparks through the wires themselves indicating bad wires.