Sup guys? So my 94 850 turbo has been running awesome. Beat a 05 rx8, 2010 sentra ser spec v, 1998 stang gt etc, I drove my car for like 4 hours straight today running errands. Went home, parked it for a couple hours, me and my dad get in it to go the store and now its not boosting, no vac leak, runs good just no boost. i dont have a boost gauge just the factory one, but if i put in sport and floor it it goes just a hair over into the white. maybe 1-2 pounds. wtf? Any insight oh fellow volvo nerds? haha

 

TCV might be bad. That's where I would start looking. Either that or the wastegate is stuck open. you might want to try to move the actuator and see if it's frozen.

 

Try carefully checking the air plumbing between your turbo and your intercooler and intercooler to throtlebody. A small slit in any of the flexible elbows might not be a problem
under vacuum , but could blow open under boost.

 

checked wastegate actuator. its good. Im resetting the ecu as we speak

 

could the cat be backed up? i did get a 555 code which is #5 misfire with cat converter damage. i fixed the misfire. but even after a 2 minute drive to see if resetting the ecu would fix it (it didnt) the cat was like tink tink tink like it was super hot.

 

so i reset the codes and the boost was back. so it was in limp mode. im gonna pull the codes again to see what i get.

 

yeah limp mode will keep the boost off. But it would be good to find out WHY it was in limp mode so that you can fix it so it doesnt happen again.