I just put a manual boost controller in my 96 850R and turned it up and dident do much and ran like crap so i just took it off and put it back to stock and now it will not boost pass 5psi. Befor i put the controller in it ran very good and boost up to 12psi. What can make it run so low boost and feels like the turbo lags from that now also.

thanks

 

hmm...check all the vacuum lines, intercooler hoses.

disconnect battery for a little then see if the ecu is back to normal?

 

Ok I disconnect the battery for one night it seems to be a little better it hits 12psi but it dosent hold it just gos back down to 5psi that's if I floor it going about 40mph if I floor it from stop it just gos up to about 8psi. Also I checked the vacuum lines and all seem fine.

Thanks

 

Did you ever find a resolution? My 850R started doing the same thing after I put the factory air box back in and removing a K&N cone filter. I have put the K&N back in and is still only boosts to 5 PSI.

 

Not sure watch one it was but I changed the CBV, the boost solenoid, and all the vacuum lines and now it allways boost to 12psi.

 

Had the same problem on my 850R. On my Stage III tune, I boost to 18psi then drop and hold at 9psi. It was my BCS. Replaced it and all is good now.

 

Its at the shop getting tie rod ends and inspections. I can pull the hose to the actuator and see if I get boost back correct? Most of the vac lines were replaced however that's a good point, I could have damaged one putting the air box back in.

I am getting ready to sell it as I picked up an S60R and now this - i don't think it wants to go though, I busted the windshield yesterday replacing the wipers and the battery was dead today, all on top of the boost issues.

 

So I disconnected the vac line to the wastegate actuator and I have lots of boost now, time for a new BCS.