Alfa Romeo Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
48 Posts
Discussion Starter · #1 ·
Hello , i changed a few months ago the wastegate actuator on my turbo. I had -1 preload , turned it 4 times to +1 preload.
A few days ago a noticed that te specific rattle started again , so i added 3 more 180 degree turns (+1.5)
So basically now i am from -1 to +2.5 preload

I noticed after that that my boost is not staying up. it oscillates - It goes up , then goes to half , up again and so . Basically this should not happen after my actuator operation , because i just tightened it up a little bit , so it should keep boost at full.

Cruising on high speed , full throttle , the error appeared and check engine and torque steering appeard . THe car lose it;s power but the steering wheel was ok.
Went to the dealer - P0638-11 Motorized Throttle valve Circuit short to ground . As they said it can be the throttle valve or the turbo , because turbo is no keeping it;s pressure. It oscilates up , down , and says there.

What i wanted to ask , can the motorized throttle valve make by boost drop ? So are they related? Or was just a coincidence this error and the car not accelerating as it should. THanks
 

·
Registered
Joined
·
48 Posts
Discussion Starter · #2 ·
Hello , came back with more info. It appears that the loss of boost is only happening after3.5\4k rpm , especially in 5th gear. The car has the tendency to hold back even if I am at full throttle. Can a cracked hose lead to this? Is the airflow bigger in 5th gear at the same rpm in 2nd and 3rd gear?.

Also , heard a strange noise when decelerating. I attached two videos. Thanks


 

·
Registered
Joined
·
48 Posts
Discussion Starter · #3 ·
Hello , I just bought multiecuscan and went for a drive on highway. Here I attached the picture and an xls file. During the test my gas pedal was fully pressed , as you can see. However , as soon as I reach 3.5-4k rpm , you can see the throttle position going a little bit lower , and same the boost. Any opinions ? Seems that the problem is actually the throttle valve , or can something else tell the ECU to close the throttle even if I have my gas pedal fully pressed? Thanls
 

Attachments

1 - 3 of 3 Posts
Top