Volvo 850 Turbo 1994 accelerating problem

gtg737m · Post by **gtg737m** » 02 Dec 2005, 06:44

Hi everyone,
Last week I changed the oxygen sensor and the mass air flow sensor of my 850 Turbo. I also need to change the knock sensors but I'll do that this weekend. After changing both sensors (oxygen and MAF) I tested my car and noticed that when I pressed the gas pedal to the limit the turbo gauge went to its limit and after it reached its limit the engine suddenly stopped accelerating. I noticed that after changing the two sensors I mentioned previously the car had more power but it doesn't make sense to me that when the turbo gauge reaches its limit the engine stops accelerating. When I was changing the sensors I don't recall missing any hose or connection to the air box. Do I have to reset the computer of the car after changing those two sensors? Is there a connection in the car that maybe I missed that controls the turbo airflow limit? I would appreciate a lot if anyone can help me solve this problem.
Thanks: Theo

email:[email protected]

White850Turbo · Post by **White850Turbo** » 02 Dec 2005, 16:28

You might want to check the connections on the BCS, which is clipped onto the airbox. A leaky hose going to the solenoid can cause symptoms similiar to what you described.

gtg737m(22) · Post by **gtg737m(22)** » 10 Dec 2005, 13:24

I finally fixed the problem of my Volvo. Apparently after I changed the front O2 sensor and the MAF sensor, the turbo was not well adjusted in relation to the readings of those two sensors. The car was boosting too much so that's why the injectors shut down when the engine reached 4000 rpm. The weird thing about this problem was that it only happened when I pressed on the gas pedal slowly and continued pressing it to go faster. If I pressed the gas pedal to its limit when the car wasn't moving the injectors wouldn't shut down at 4000 rpm. Anyway, I took my car to a Volvo dealer and they adjusted the boost pressure and the car is running fine. I first took my car to a normal Volvo shop and they were not able to figure out the problem. I guess Volvo dealers have the right equipment to figure out any problem a Volvo has. I was charged $220 but my car is fixed.