I have a 300 six with the original feedback carburetor and EEC-IV computer. Timing is set to 10 BTDC with the SPOUT disconnected. When the SPOUT is connected it goes to about 20 BTDC at idle. When the the engine is revved to around 2500 RPM, the timing mark goes way off the scale, maybe 40-60 BTDC and the engine knocks like a diesel. When driving the engine knocks at the end of each gear range. If the truck is driven with the SPOUT disconnected, there is no knock and it drives fairly well.

This truck is something I have owned only a short time. When I bought it there was no knock because there was no power running to the EEC. The knock started when I got the EEC powered. I have replaced a few parts and the EEC now has no codes.

Wondering if there is anyone with expertise in this relic that might know what would cause the EEC to advance the timing too far. Also wondering if maybe its worn out rod bearings rather than a timing issue.

 

That is normal
You will see it approach 40 BTDC at times
The processor takes over once you plug the spout back in
The kicker is to get the base timing set to ten before with the spout plug out or unplugged.
Then you are good to go
007