Fisheroon
New member
Hmmm well that is odd about the restarting thing. I may very be incorrect on my original guess. A scan tool should be able to verify if what I thought is true (basically find the PID for “fuel control” or “fuel system” and it will say either “open loop” or “closed loop”. Closed loop means the computer is in full fuel control and will do whatever it takes to keep emissions down and run at 14.7:1 AFR. Open loop means it will add fuel based on demand, basically, and ignore other parameters to complete the task.
Open loop: engine temperature cold, load demand is high (wide open throttle/80% or more throttle demand) etc
Closed loop: engine warmed up, load demand is low, cruising around, weak throttle demand etc.
That’s the best I can describe the 2 operating modes.
I would try and verify what the main computer is doing when you experience your symptoms.
The timing control is always active, but is more effective below 3K because yes the main computer ignores the knock sensors. That being said, changes to timing above 3K does help protect the engine by expanding the affective safe zone in which the computer can operate (the computer can only change timing so much, and by changing its zone it allows it to operate less “on-the- edge” of its zone). That’s my understanding.
Thanks, that's a great description of the operating conditions and helps to clear up my confusion. I'll see if I can use my bluetooth OBDII app to read those PIDs.
I would love to figure out this problem so I can fine-tune the fuel/timing maps a bit. It runs so much better after restarting but I can feel it pulling timing and losing power. I would love to smooth/reduce the timing table out a bit. It just makes it really difficult when the truck seems to have two "ECU maps" depending on whether or not I restart it...