The emission certification test cold start is begun after soaking the car at 70F for at least 12 hours. Because about 80 percent of emissions are generated during the first two minutes of the test, the OEMs calibrate a 70F cold start on the ragged edge of leaness, which can cause the car to start and die.

Most may notice that their CIS-E equipped cars cold start much better at less than 50F.

One way to mitigate the problem is to adjust the duty cycle (search archives if you don't understand this term or how to adjust) to below 50 percent at idle. The max differential between idle and 2000 rev duty cycle is specified at ten percent, so if you adjust the idle duty cycle to average about 45 percent (slightly rich) it will probably be about 55 at 2000, which is okay.

Duke