Originally Posted by Realale

I just had an issue with my Stillen kit, but not the same. First the engine light came on after running hard for about 5min. Also would always idle with a constant 300-400 RPM swing. I took it back to Stillen to get fixed and it was one of the throttle bodies sticking. So they replaced it under warranty and ran great.

Then I started having a hard time starting the car. It would always start, but take a few cranks to fire up. And then kinda sputter to get going. So I took it back to them and it was a small pin hole in the fuel pump fitting. Keeping it from holding fuel pressure. They replaced the hose and all has been good since.

If you can try to read the code with a reader and then you will know where to start looking. Also you might try to turn the car to the "ON" position for a few seconds without your foot on the clutch. Then turn the car off. Then you can try to start it. Hope you get the issue resolved soon and get your Z back on the road. Keep us posted with the results.