Contour Enthusiasts Group Archives Forums General Troubleshooting Duratec secondary intake runner blues

IF you flip the throttle wide open, while the engine revs up, when the RPMs reach about 4000, on an ATX Tour, there is a spark knock-off that limits the rpms.
This is so you don't damage the Torque Converter.
When you release the throttle, the IMRC will open the secondaries to allow additional air into the cylinder to increase the rate the rpms drop.
You can also do this with any MTX Tour and see the same action.

Pete...