1228747 Tunerpro Datalog -show no value change on MAP sensor reading

[Blazeone]

Hello ,
1990 c2500 Hd above 8500lb gvwr
stock engine , stock everything.
350 tbi with th400 trans.
1228747 ecm
Poor off idle acceleration and power loss. Runs great at highway and once it's gets past initial acceleration from a stop.

Tunerpro connected, engine at 189* data log is not showing a change in MAP readings.

The Voltage reading will change with accelerating(throttle position) BUT the kpa/in hg reading stays at ~26 in.hg.

I hooked up up a mechanical vacuum gauge and saw 22" of vacuum at idle and when I blip the throttle the vacuum would drop to 0 ( like it should) . Then return to previous reading.

so if my Aldl data log info doesn't change regardless of throttle position .... does this indicate a faulty MAP sensor unit.???