91 b2600 intermittent hesitation issue.

hey guys new to the forum havin a acceleration issue with my truck has 338xxx km on her but i love it and wanna keep her goin

so ill be accereating and sometimes it will either struggle and have no power for 1000-1500 rpm the kick in and go full tilt. sometimes its fine. and i have no problems.


ive done a full tune up on it.plugs wires cap rotor fuel filter ignition coill. ect.
also replaced ECU and Distributor with **Brand new parts not re maned. has proper timing in it however im sure the timing chains are worn. any help would be awesome. having trouble findimg technical help!! thanks!

also ran tests on the coolant temp sensor and it came back as normal. did a fuel pressure test it came back nominal and the fuel pressure regulator has been chamnged.

With the distributor being replaced, should not be bad module. I lean toward a bad ecu. I read on here alot about this happening and being that. Do you know anyone with a '90-'93 B2600 that likes you enough to let you pull and try there ecu?