Hello, I have a 98 GS-T. When the weather was warmer the car started fine. It is now cold and it is having a difficult time starting. It only has trouble in the morning on its very first start. It idles very low (approx 100 rpm or less) and i have to crank it longer than normal. When i hold the key while cranking it idles low and slowly brings its way up to normal idle. The car shakes like it is about to stall. The battery is fine. Any ideas of what to check?