So i was offered a good deal on an s2000. F20c with a BC 2.4 stroker kit, and bc head package, car is running on haltech primium. Supposably has 16k on the motor. Long story short, A freind of mine who owns a speed shop was given it becuase someone owed him a nice chunk of money. Cars starts and idles great. Drives great. No ticking no knocking. Butt the issues is when it hits vtec it breaks up.. My buddy and his mechanics think its the tune. I can tell it is deff running rich, by the smell and it blows a little black smoke. Any ideas?!! Please help thanks!!!!!

 

You need a tune.

 

I agree. A tune would prob help a lot. You might want to get a wideband meter to keep an eye on the afr. "Breaking up" could also be ignition. Either way a tune would help assuming nothing is broken of course. Good luck man.

 

have you checked the plugs?

I'm sure a retune can help, but vtec is really controlled by the vtec solenoid and coolant temp being at the appropriate mark.

First thing I would do is pull the data logs from haltec and the obd2

btw if it is running that rich its probably killing your cat and o2 sensor as well

 

Vtec can actually be controlled and handicapped more ways than that. With ems vtec can me controlled by the ecu using engine load, speed, and rpm, thus is why many delete the sensor attached to it. A re-tune will not only help, but potentially FIX the issue, along with any other issues to may have. One of the things don't in a re-tune or any other tune is data logging...