My car seems to suffer from cold start hesitation pretty badly, almost undrivable until warm. However, sometimes it is fine.. I was finally able to capture it in a log and noticed that between about 40 and 50 degrees c, when opening the throttle, the ecu does not advance timing at all, it will remain at idle gear timing (15 degrees for my setup). once it hits 50 degrees, the timing will suddenly advance and correspond to what is shown on the timing map and will run fine. When its colder than 40ish, it will operate normally as well, and run OK. This is really odd, my TPS is functioning correctly under these circumstances, and i have no trouble codes shown. any idea what could cause this to happen in this temperature window, and be somewhat intermittent? CHTS also seems to be fine, as im always getting normal readings displayed in the consult guages display. TP varies, AFM signal varies and TPS opens and closes but timing will remain constant no matter what. If i drive it hard, it will clear up over a certain rpm, probably near about 2800, but will continue to run like shit untill warm or held above this rpm level.
EDIT: also, when at idle, (tps on) timing is advanced as per cold start table. once tapping the throttle, it goes to 15 deg and stays there.
Interesting cold start timing issue... need help!
Moderator: Matt
Nissan uses min temp, rpm and tp values to tell/force the ecu to use the idle timing maps. What happens when you adjust the k value and the tp scales the min tp value now ends up being in the 3rd or 4th tp column while stock is just over the first tp column value. The min tp value needs to be changed to represent the new load scales.