Hi and welcome. what model Volvo do you have? have you check all intake hoses and vacuums?
do you have any codes or is the check engine light on?
has any parts been replaced?
was the fuel filter replaced also?
if your filter was clogged it wouldn't make a difference if you replaced the pump or not the filter comes after the pump.But if you feel the filter is not the issue then when were the ignition wires and cap and rotor replaced?
17000 miles ago
how many miles does it have now and have you looked at these parts?
on the intake air hose you will see a sensor with a plug just before the the air box this is the air flow sensor. start up and disconnect if idle changes or the car continues to run this is your problem.
sorry didn't here from you so I went offline. wouldn't be 02 sensor.. The car seems like it isn't getting enough fuel.I need you pull the plugs and describe what they look like.
usually the throttle problems are to do with electronic throttle no manual like yours,i would check anyway you seem to have a unique problem. let me know.
try tapping the idle control valve silver cylinder thing that has 2 hoses going to it and a 3 prong plug at the top by the throttle you just cleaned.
this just means there is to much air which says theres not enough fuel which why you get that 172 code lean condition. You will need to check the fuel pressure since you have replaced the fuel filter and pump then you may have either a problem in the lines or the tank.