Well...morning has come..
I went out and tried a few things and got subtle results...nothing FIXED it completely.
Prior to the following checks I removed the DPFE and checked to see if there was any evidence of corrosion or carbon fouling. It was sooty but showed no signs of being gunked up or moisture contaminated. You can't see much of anything down the two ports. I shot some carb cleaner down the ports and "aired" them out before the runs.
First I disconnected/plugged the vacuum hose to the EGR valve diaphragm and it seemed a little smoother.
Next, reconnect vacuum hose and disconnect the DPFE connector...that produced the best results, however it was not gone.
Third, I left the DPFE disconnected and also disconnected/plugged the EGR vacuum hose...not much if any difference from the previous run.
Conclusion...this might be a contributor, however I don't think it is the total answer.
...Ed
