Load Related Idle Surge
49k original miles
Repair history: head gasket had slow failure causing coolant consumption, replaced and engine ran well. Idle speed under longer engine run times would hunt and be more dramatic under load like ac etc. New OE throttle body. Found an Identifix post about these transmissions having bad torque convertors (among other things) causing engine load in gear and sure enough, this unit failed the psi test chart and fluid was black and full of fine debris. Now with reman Ford unit, and solenoid/shift strategy updated with IDS, idle still bad. Can't find any info about Idle Relearn Procedure. KAM reset, and so was misfire profile correction, or whatever Ford calls it. Letting it idle and correct itself has been pointless thus far
Idle speed will be normal from cold start, and engine runs fantastic with no codes or concerns. At idle, especially in gear and with any accessories running, the idle will rise and fall like an older Honda with vacuum leak. Has even caused a rare stall for customer before the transmission repair.
Fuel trim always within 2% total, both intake and exhaust cams showing < 1 degree difference (usually like 0.0 to 0.4 degrees to be exact). I took images of scan data, and I feel like the turbo wastegate pid is a silver bullet that I don't know how to use. It jumps from 0% to 85% and what I can find says this is PCM duty cycle control. But, the Ford chart also says that this command should never be above 19.75% at idle, and mine goes to the full 85%. Is this pid stating command? I feel like if I could just tell it to stop engaging the wastegate we'd be fine….
2 scan data images show the fluctuation in park, 2 show it in drive.
I have images of running compression wave forms. idle, and snap throttle.
I am not well versed in the delicate changes expected in the waveform of variable valve timing engines. I am using a basic snap on compression gauge hose to take my sample and a Fluke pv350 on cylinder 1, with coil #1 on channel 2. sorry for the secondary causing the compression waveform having a dirty signal, but my coil was less than 3 inches away from the fluke during testing.