im new to this site and i have tryed several things like new plugs wires and cap rotor and air temp sensor.
but still no fix to the problem.

ive been told could be dirty air control valve or a clogged cat but im not sure going to try the air control valve please need help thanks

 

the idle air controller is only invoked at idle, with your foot completely off the gas.

bogging down when accelerating could be from air leaks in the intake path, or it could be from weak fuel delivery. or it could be something completely different, hard to say.

is this 1991 a Bosch or Regina car? does it show any OBD diagnostic codes? (you don't need any scan tools to read the OBD codes on a 1989-1995 Volvo, just follow these instructions: Engine and OBD Diagnostic Codes and do "DTM #1" which is reading the codes. there's two sets of codes, jumper on pin 2 for fuel injection, and pin 6 for ignition controller.

 

Fuel pressure regulator, temp sensor and lifter pump in the tank are suspects. The type of fuel injection makes a difference though. Codes are your friends too, so +1 to Pierce's suggestion.

 

A clogged fuelfilter?