I have a 1995 Gas Inline 6 E-320 and it has problems.
It Hot or Cold:
The Idle jumps. In Neutral more so than Drive.
Cold:
Drives Great! Lots of Power.
Hot:
Under Loads and at Stoplights it chokes then restores power, then chokes worse and restores it'self etc.Must put in neutral to keep from choking.
All of the sudden there is as loss of power. Floor it, the engine revs (only to 4,000rpm though) and there is no response from the engine with power.Just nothing, you slow to a stop.

Any suggestions would be great.
Billy

 

I am reviewing this same issue and, I believe, getting closer to the solution albliet on a 1990 300 motor...it is vexing for sure...cliff

 

Air-idle-valve? Might have sucked somthing into it.

 

Is there an Air-Idle valve? Is that the Mass Air Flow you're talking about?