I have a 2000 s2000. The vtec is engaging properly, that has all been checked. With the vtec unplugged, so it does not kick in, the car runs great. However, with vtec plugged in, when it kicks in, the car runs horrible, like it is starving for fuel or air, and it sputters and has no power at all. It has plenty of fuel pressure, is getting plenty of fuel. We hooked up a fuel pressure gauge and an air fuel gauge. It is running right where it should be. Airflow is great to the engine. With vtec unplugged, it pulls hard all the way to 8000 rpms, but when it is plugged in, it runs fine until 6000 when vtec kicks in, and then just has no power. Does anyone have any idea what this could be?

 

Is the check engine light on?

 

Thats the opposite from what should happen, I'm surprised it will even get that high in the revs without needing the cam switch.

I take it you haven't done any head work before this problem occurred?

How exactly are you "unplugging" the vtec?

 

I'm assuming he's unplugging the VTEC solenoid, which in of itself should turn on the CEL.

 

There is no cel, and I am unplugging it from the solenoid.

 

It will rev to 8000 with it unplugged just fine, but really does not build power after about 6500. With it plugged in, the vtec kicks in at 6000, and as soon as it kicks in it has hesitation, and doesn't want to go.

 

Does anyone have a pinout for the s2000 computer?

 

No headwork done at all. I hooked up a greddy emanage computer, and the car would not run right at all, unhooked it and now this is the problem I have. I don't know if I hurt something or what happened, but I have it wired back to stock, and have double and tripple checked the wiring, and am pretty positive it is correct.

 

Hows the compression on the engine?

maybe theres a problem with the valve springs :thinking: was the engine accidentally over revved in a down shift?

 

compression is fine, and it was not overrevved. Like I said, with the vtec solenoid unplugged, the car runs perfect.