Hi, having trouble with my s40, its a 1998 20t with the b4204t and 5 speed. I have a couple of issues with it atm and thaught i might ask for some advice on here.
Iv been searching the internet and volvo forums alot looking for answers,

1st problem is starting up the car, it takes a while to fire.
So far iv replaced
*fuel pressure regulator, baught from volvo dealer
*brand new fuel pump and filters
*brand new fuel filter underneath the car
*swapped out injectors with some second hand injectors from a 98 t4.
I swapped everything in that order and since i swapped the injectors its harder to start.

2nd issue is boost
I installed a boost gauge and was only getting 3.5psi, i disconected the tcv and fitted a mbc. I wss still only getting 3.5psi so i adjusted the mbc 1 turn and had 5 psi, i adjusted it in again and only got another 1.5 turns and it is adjusted all the way in and im only getting 6.5 psi. Im not sure what to look for next. Any help will be greatly appreciated, thank you in advance

 

Did you try inspecting/testing and cleaning the idle air control valve and MAF sensor? Are you getting any check engine light codes to suggest a weak spark - when was the last time the wires, plugs etc were replaced? What do the plugs look like??