Here's something which may or may not be one of those oddities.
A couple of years ago on a trip, I noticed that sometimes (not all the time!) my completely stock '04 sputters, coughs, and runs quite rough when started from cold (like after having sat over night.) The check engine light lights up, which is scary enough in itself. I interpreted this to a problem with the cold bike not getting proper air-fuel and/or timing settings.
But I soon discovered that if left alone to warm up, once the temp come up to something approaching normal operating temp the thing smooths out as though nothing happened. I also came to notice that the problem only occurs when the bike is at some kind of elevation e.g., in the mountains or hills above about 2000 ft. When at home, which is at roughly sea level, there is absolutely no problem with startup from cold.
Except this morning! I fired up the bike and it sputtered for about 10 seconds. BUT today a low pressure front is moving through the Willamette Valley, where I live.
The questions:
1. Does barometric air pressure play a role in how the ECU functions?
2. Is the ECU the culprit?? :blink:
TIA for your thoughts.
Bob
A couple of years ago on a trip, I noticed that sometimes (not all the time!) my completely stock '04 sputters, coughs, and runs quite rough when started from cold (like after having sat over night.) The check engine light lights up, which is scary enough in itself. I interpreted this to a problem with the cold bike not getting proper air-fuel and/or timing settings.
But I soon discovered that if left alone to warm up, once the temp come up to something approaching normal operating temp the thing smooths out as though nothing happened. I also came to notice that the problem only occurs when the bike is at some kind of elevation e.g., in the mountains or hills above about 2000 ft. When at home, which is at roughly sea level, there is absolutely no problem with startup from cold.
Except this morning! I fired up the bike and it sputtered for about 10 seconds. BUT today a low pressure front is moving through the Willamette Valley, where I live.
The questions:
1. Does barometric air pressure play a role in how the ECU functions?
2. Is the ECU the culprit?? :blink:
TIA for your thoughts.
Bob
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