Today I got really fed up with some stuff my truck did, like having a little inconsistant shift points to OD, going in and out of lockup etc. First I thought about using a bigger capacitor to filter more noise. Then I thought what the heck...

I cut off the OR/DB cable from pin 28 on the ECM and replaced it with a re-routed shielded cable to the PCM.-Same colour there, everyone who has a noise filter in place knows this bugger
(And removed the capacitor. )
The result- Consistant shift points, rock-solid OD and TC engagement, cruise working much nicer and surprise- much smoother running engine.
The only way I can try to explain this is that with the capacitor filtering on the PCM side of the circuit the APPS input of the ECM gets the noise. (like a capacitor and a coil forming a resonant circuit) and making the engine want to respond to the perceived movements of the go pedal.
I routed the shielded cable along the firewall to the PCM- it was some work, but well worth it. A big capacitor in the line as a noise filter has some disadvantages IMHO- first of all it will delay TC unlock if you step on it and TC re-lock when you cruise after that, second (if big enough) it will make the engine respond slower. (I think that the APPS voltage will ramp up slower due to the added load for charging the capacitor)

Just thought I'd share this

AlpineRAM

Disclaimer- If you decide to to the same verify cable colouring and you do so at your own risk!