I have a stage 2 so normal boost is max 16lbs, but now im boosting max 12.5.

Someone said something about if the ecu recognizes, valvetrain abuse, innercooler pump failure, and a few other problems, that its possible the ECU will limit boost to about the 12.5 range as a way of self preservation.

I found that my IC pump was leaking, and had low coolant, so i fixed the leak and filled her back up as well.
Could this of caused the problem?

I also feel that the car is running a bit rich now as well since there is now carbon build up on the lip of my bumper by the exhaust which possibly leads me to think that the ECU changed around the tune a bit.

The car still runs strong but lacks at the upper rpm, and its not the boost gauge since i have a LED that lights up at 10lbs when my meth kicks in and its still right at 10lbs.

If someone has some expertize please chime in its bugging me soo much!

edit: It also has increased vacuum at idle.

 

Bump for more info!

 

Check to make sure the pump for the inner cooler is working.

 

It is/bump

 

check boost sensor, i had to bring it to dealership to have them check it but that was my problem. i was only getting 7 lbs

 

i dont have an intercooler pump at all could that be causing my car to dump boost

 

What are you driving and list your mods if you dont have a pump.

Heres the Info for you,

Supercharger boost pressure is regulated to prevent engine and drive train damage. When the engine is operating under high boost conditions, the powertrain control module (PCM) limits boost pressure to 83 kPa (12 psi). The PCM disables boost under the following conditions:
• When reverse gear is selected
• When the engine coolant temperature (ECT) is excessively high
• When drivetrain abuse is detected
• When the vehicle is decelerating

I would be looking at these two
• If an intercooler pump failure is detected
• If the intake air temperature (IAT) sensor 2 becomes excessively high
• Under heavy load in first and second gear at engine speeds above 5,800 RPM

 

subd for reference

 

bbv may be bent and stuck open?
has happened to others on the forum

 

i'm having the same EXACT problem!!! same boost numbers and everything!

 

Do the boost bypass mod and then you can see if that changes things.

 

didn't change anything for me

 

Belt slip....tensioner going bad?

 

i did the boost bypass mod and i get boost again
but i rather find whats wrong than run with a plug on

 

it does not feel like belt slip, it builds boost pretty steady and then just stops. it doesn't really surge or anything

 

will an exhaust leak cause low boost? like pass the cat?

 

Nothing wrong with that. Boost is just mechanically controlled now. Others can step in who are more familiar with the electronic system.

 

You are going to have to find out what is causing the car to limit the boost. If you are under warranty take it to the dealership. If you aren't in warranty you need to find someone who can log the car. There could be a number of issues that can be causing this. If you accelerate up to 60 - 70 slowly then downshift to third and punch it does it ever hit above 12.5? Do you ever see it go above 12.5 at all?

It is possible the IC pump is out, but if you punch it when the charge air is still cool you should see it at least hit ~15 then as the IAT2 gets to high it would drop to 12.5. You could be getting knock and it is pulling boost because it is detecting "abuse". It could be the actuator for the bypass. The list of possiblities can go on and on... If you did the boost bypass and boost was normal again I would start with the boost bypass/actuator first. If you replace that and it is still doing it then you will need to get a log.

 

i unpluged the battery in the back and left it off for the whole night
now i have moar boost again, back on boost