Hi
I've a 2006 S/C Cobalt SS and have upgraded it to the stage 3 kit from CA which should increase the boost level to 18 PSI. (+65HP PCM retune 2.7 pulley shorter GM belt 42 lbs injectors)

http://cobalt-addiction.com/performance.htm

after I installed the kit everything worked fine and I got a nice response from the car. Now 2 weeks later the car is not boosting 18PSI anymore but only 15 PSI does anybody have an idea of what the problem could be...?


thanks in advance

 

sounds like a boost leak somewhere.. do u have a mechanical boost gauge?

 

No I Don't

I got a response that is telling me

"I would bet about 90% that the problem is the supercharger bypass vacuum solenoid"

which solenoid is the bypass vacuum solenoid?

 

Could be the 42lb injectors are restricting the psi?? maybe??

 

are you seriously running 42's on a 2.7? Get a bigger pulley on there ASAP you are working those injectors hard.

 

im running a 2.7 on 42#s never had a problem its been over a year

 

doesnt CA sell the stage 3 kit with a 2.7 and 42s? pretty sure they do

 

Yes they do I bought it like it is with the 2.7 and 42lb injectors

Stage #3 : 2.7 ZZP Interchangeable Pulley system , 1 step colder ngk IRIDIUM spark plugs , GM shortened belt , 42# Lucas Injectors , Injector Wiring Harness, Stage #3 Retune ... Est. 65 Hp over stock - 18 psi boost


Stage #3 Your Price: $579.99 USD


did you change your tensioner for the adjustable tensioner maybe...?

 

the pulley size is a 2.79 i believe

 

thanks for all your help and replies on my post

the problem of my car was the boost gauge which was faulty
I changed it and wow.... again like it should

 

i would be carefull with those 42s and a 2.7. The **** is going to go BOOM soon!!!!!!