Lately I have been playing with Torque Pro to observe and log data from the truck as I drive around town. This is a fantastic app that works very well.
Since the weather has warmed up, the truck has started doing a strange thing with timing. I believe it starts after the truck has entered closed loop operation. It is retarding the timing like crazy when you start to accelerate. Also when sitting in gear at a light, the timing is all over the place, but the idle remains smooth. Turn the truck off, turn it back on and it is normal again. I do not think it is related to my phaser lockouts because others have reported the same sort of bog when the weather is warm/hot.
To enter closed loop, certain conditions have to be met:
Torque allows you to log a ton of info. I didn't have a good way to view it though until I found www.datazap.me. I like it because it is online based and I can view logs at home or at work.
This screenshot is from yesterday when I was sitting waiting to pick up my kid at school. Closed loop. Most of this is me sitting idling in neutral. Note that the timing is wandering a little (a few degrees), but is generally pretty consistent. Just after the weirdo spike (what the heck?) I put it in gear, held my foot on the brake (note the area where the rpm drops down and vacuum drops) and the timing just goes bonkers. Once I put it back in park, the timing stabilized somewhat. Weird stuff, but definitely interesting.
Not sure exactly what is going on there. Prior to switching loops, the truck runs great. After switching modes, which I believe is in the area of 550-600 seconds after startup.
I'm going to keep logging different parameter and see what is causing this.
What I REALLY need is an exhaustive list of PIDs and their formulas for this ECM (2007 F150 - 5.4L). There is just not a whole lot of info out there about it though.
Since the weather has warmed up, the truck has started doing a strange thing with timing. I believe it starts after the truck has entered closed loop operation. It is retarding the timing like crazy when you start to accelerate. Also when sitting in gear at a light, the timing is all over the place, but the idle remains smooth. Turn the truck off, turn it back on and it is normal again. I do not think it is related to my phaser lockouts because others have reported the same sort of bog when the weather is warm/hot.
To enter closed loop, certain conditions have to be met:
When the engine is first started, and rpm is above 400 rpm, the system goes into 'Open Loop' operation. In 'Open Loop', the ECM will ignore the signal from the Oxygen (O2) sensor and calculate the air/fuel ratio based on inputs from the coolant and MAF sensors, but mostly from a pre-programmed table in the memcal.The system will stay in 'Open Loop' until the following conditions are met:
1. The O2 sensor has varying voltage output, showing that it is hot enough to operate properly. (This depends on temperature)
2. The coolant sensor is above a specified temperature about 40oC/104oF.
3. A specific amount of time has elapsed after starting the engine. (some say around 700 seconds, but this could vary by model)
The specific values for the above conditions vary with different engines and are stored in the mem-cal. When these conditions are met, the system goes into 'Closed Loop' operation. In 'Closed Loop', the ECM will calculate the air/fuel ratio (injector on-time) based on the various sensors but mainly the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.
1. The O2 sensor has varying voltage output, showing that it is hot enough to operate properly. (This depends on temperature)
2. The coolant sensor is above a specified temperature about 40oC/104oF.
3. A specific amount of time has elapsed after starting the engine. (some say around 700 seconds, but this could vary by model)
The specific values for the above conditions vary with different engines and are stored in the mem-cal. When these conditions are met, the system goes into 'Closed Loop' operation. In 'Closed Loop', the ECM will calculate the air/fuel ratio (injector on-time) based on the various sensors but mainly the O2 sensor. This allows the air/fuel ratio to stay very close to 14.7:1.
This screenshot is from yesterday when I was sitting waiting to pick up my kid at school. Closed loop. Most of this is me sitting idling in neutral. Note that the timing is wandering a little (a few degrees), but is generally pretty consistent. Just after the weirdo spike (what the heck?) I put it in gear, held my foot on the brake (note the area where the rpm drops down and vacuum drops) and the timing just goes bonkers. Once I put it back in park, the timing stabilized somewhat. Weird stuff, but definitely interesting.
Not sure exactly what is going on there. Prior to switching loops, the truck runs great. After switching modes, which I believe is in the area of 550-600 seconds after startup.
I'm going to keep logging different parameter and see what is causing this.
What I REALLY need is an exhaustive list of PIDs and their formulas for this ECM (2007 F150 - 5.4L). There is just not a whole lot of info out there about it though.
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