1996 850 t not achiving full boost pressure

jaatee · Post by **jaatee** » 19 Oct 2009, 19:33

1996 850 t ISSUES- According to a Volvo Specialist,I have a fuel metering problem as well as possible vaccuum issues.The car runs smooth,ok, except when the pedal hits the floor the turbo boost doesnt go above 5 lbs.A OBD test will tell me more...I will be buying all tune up parts ,but since the turbo(ie-specifically the valve relating to boost pressure)and fuel system are controlled by the same ecu ,should I replace it or need too?

Post by **MadeInJapan** » 20 Oct 2009, 15:49

If you're asking about the ECU- no.
It usually is not the culprit- instead, the lines to and from the turbo as well as PCV lines AND the turbo control valve (TCV) as well as the wastegate and turbo itself should all be checked. Any of the large intercooler hoses (if they are torn) will also produce lack of pressure.

jet_brick · Post by **jet_brick** » 29 Oct 2009, 16:26

You might as well start by replacing every rubber elbow and cracked vacuum hose / line. Check to make sure the vacuum tree's non-utilized ports are capped off snug. Replace the turbo/intercooler hoses with a silicone set, not cheap but worth it. Make sure youf codes are clear. Resetting the codes if they have been there for a while will make a big difference. My old 850 wouldn't boost past 5psi when it had stored codes like 232, etc. I would say it's a leak in one of the turbo hoses (just remove each and every hose to check, trust me) make sure the clamps are on good, get all new vacuum lines and rubber elbows. It will prob be one of the above.

Steve Wiener · Post by **Steve Wiener** » 16 Dec 2009, 11:02

usually u can see a rubtured turbo hose by oil coating it.