3.4 Timing

I generally put this in the tech section, it does not get much traffic, and I would like an answer sooner than later.

95.5 tacoma (duh) 3.4 4x4 manual trans.
I have a lack of timing advance in the 3k-4.5 rpm range.
It is not advancing timing at steady state driving ex, @60 and accelerate , timing drops to 2- 2.5 maybe 10*

Let off the throttle and timing will jump to 30* , and I use this as an example.

I figure cam ,crank position sensors, as well as tps and maf, should be components that communicate to the ecu timing.
I have no codes, just the sotp, and live data to verify.
I don't want to throw parts , to maybe fix the problem.
I want to know how and why I have the problem, and how to verify and fix.

Thanks
Ashley