1996 850R Low boost pressure at Full throttle

gmtgmt · Post by **gmtgmt** » 28 Jan 2015, 13:25

I have a 850R 96 B5234T5 Automatic in the shop with boost problems.
Heres the full story on the car and its giving me headaces.

First it had no boost at all TCV was bad, This was replaced with a IPD HD Unit,
But these mods where also done along with the TCV 3" downpipe with Cat (BSR) and 2.5" cat back mounted. Along with an Angled turbine hosing (because the Down pipe Came that way) and a 2001 2.5T Japan exhurst Manifold not R manifold but better than stock.
The boost was turn up abit not alot maby 0.2Bar from stock

After that it would cut out hard when accelerating full throttle, Boost where Turned Down to stock still the same,

the owner changed the Sparkplugs him self OEM Volvo plugs, but broke 2 and pieces fell into the engine and he started it sounde horrible, no damaged to the engine, Had the head off found the piece in exhurst turbine housing, and a cracked blade.

a good known used 15G was fitted, CBV Replaced, Wastegate checked.
5 new plugs I put in along with full service all fluids and filters.
used fuel pump from wrecked T5 i had that worked and New Volvo Fuel Pump Relay.
All Vacum Hoses was replaced also.
New OEM MAF

Now the it runs great and pull like 850R does and alittle more the turbo boost gauge moves almost out of the scale, but only at half throttle, when you full throttle it dosent seem to make alot off boost, gauge only show 1/4 in to the White area and slow just like with Theres a blown intercooler hose but non seam bad,

Anyone have any idea what the problem might be.
The car is going to sweden to BSR and put on a Dyno and have a Tune in the box when the car is fault free.

huzzsaba · Post by **huzzsaba** » 28 Jan 2015, 14:28

check vacuum lines. Any codes?

gmtgmt · Post by **gmtgmt** » 28 Jan 2015, 14:30

all Vacum hoses are replaced and recheck, No Codes

Post by **matthew1** » 28 Jan 2015, 15:11

Sounds like a hose collapsing or blowing off on full throttle.

Post by **scot850** » 28 Jan 2015, 15:36

Try swapping out the IPD TCV for a known good OE TCV. I had problems with my IPD TCV due to poor installation instructions from IPD even after calling for info and clarification.

What I figured out is you should only wind the front 'L' shaped pipe in 3-4 turns max. If you screw it all the way in it pushes the little gauze filter back against the valve, which prevents it working correctly or in worst case at all. I had them send me a replacement body and then carefully wound the front leg in only 3-4 turns MAX!! Yes it feels loose but they tell me is ok. You could always try some thread tape if you are worried, but as it is plastic, be careful not to damage the threads.

Hopefully all will be good as you have tried all the fixes as I did, until I figured this out. Luckily I had a spare OE TCV to prove the point.

I did write to them and suggest they clarified the instructions.

Neil.

gmtgmt · Post by **gmtgmt** » 28 Jan 2015, 23:01

Awesome will try the TCV from my car on it insted, and will check the hoses.