A well known professional transmission rebuilder has informed me that an engine that is starved for fuel will cause late and hard transmission shifts.
Here's what he said exactly:
"One thing however, now that you mention this... suppose that the transmission shifts late when it shifts hard (when it appears to get hot)... This would probably mean that you have an ENGINE problem... When the engine is not running correctly, it may demand more throttle to make the car go, which would pull the cable more, causing late shifts, AND, drop the vacuum, causing harsher shifts. We see this when the vehicle has a plugged fuel filter, etc... The more starved the vehicle gets for fuel, the more the driver steps on the throttle, which delays upshifts and harshens the shift, as well."
I don't quite understand or "get" how exactly his makes any sense!? Late shifts are SUPPOSED to be hard, right? I just don't see how a non-electronically shifted transmission can somehow KNOW that you're stepping on the throttle more than normal because the engine isn't getting enough fuel??
Anyone?