My Pulsar with an E6i works fine in the cold mornings, I just try not to drive it hard (Hard not to do with 70hp) if I can't wait for it to warm up. But if I do let it run, I just wait until the engine drops below 1000 RPM idling. (Starts off at about 2300RPM cold and while warm idles at about 750) Usually 3-4 minutes. My car doesn't give me any trouble (yet) if I run her hard while still cold anyway.