1-7-2010 - Cold start bouncing idle and rev hang

Vit and I have been trying for days to troubleshoot an issue we've both had with our cars during cold starts. I emailed Doug at Hondata today asking if he had any ideas.

He suggested that we block air from this cold start thermostat valve. It's supposed to supply additional air to the injectors through small channels in the head and intake manifold to help atomize the fuel as it enters the cylinders. Well, with the injectors we're both using (RC) this doesn't seem to work too well. It seems that instead, the air gets sucked through into the cylinders without changing the manifold pressure and freaks the computer out.

We both cut and plugged the hoses for this and voila, no more rev hang and bouncing idle. Who would have thought?