boost not right

[golden1663]

Hi ya:
can anyone tell me that why my car boost is going up and down ?
ie : it try to hit 0.9 bar and then drop a bit and then try it hit it again ?
is it fuel cut ?
Do i need to change the fuel pump or injecter?
help?



My car had fitted : HKS evc , Apexi AFC , HKS air filter, full system exhuast , decat , boost set low 0.7 ,high 0.88.

thanks

[Wodjno]

Hi ya:
can anyone tell me that why my car boost is going up and down ?
ie : it try to hit 0.9 bar and then drop a bit and then try it hit it again ?
is it fuel cut ?
Do i need to change the fuel pump or injecter?
help?



My car had fitted : HKS evc , Apexi AFC , HKS air filter, full system exhuast , decat , boost set low 0.7 ,high 0.88.

thanks

Hi .. If it's an aggressive drop , then yes it's fuel cut .. If it's more gradual then you may have a leak somewhere ,but normally if you got a leak it will not regain the lost boost but stay at the lower level .. If it is Fuel cut , changing your injectors or fuel pump will not make any difference , you need to overide the ECU with some kind of fuel cut defender which can be purchased fairly cheap . But this is not advised as it overides the safety system set into the car that stops the turbo's from overbootsing and doing serious damage to you engine ..
Hope this helps ..

WODJ

[golden1663]

Hi .. If it's an aggressive drop , then yes it's fuel cut .. If it's more gradual then you may have a leak somewhere ,but normally if you got a leak it will not regain the lost boost but stay at the lower level .. If it is Fuel cut , changing your injectors or fuel pump will not make any difference , you need to overide the ECU with some kind of fuel cut defender which can be purchased fairly cheap . But this is not advised as it overides the safety system set into the car that stops the turbo's from overbootsing and doing serious damage to you engine ..
Hope this helps ..

WODJ

it is not a aggressive drop , but you can feel the car is not boosting smootly ?
how can check the leak from ?
anyone can help?

[Wodjno]

it is not a aggressive drop , but you can feel the car is not boosting smootly ?
how can check the leak from ?
anyone can help?

You will just hav to check all the piping from the Turbo's to the Manifold .. Also check all the little attachments to the manifold to make sure there isn't any missing or open .. Or you may have a faulty Dumpvalve ..
Theres probably some other options to and sure some other Member will be able to point these out to ..

[enigma]

Hi ya:
can anyone tell me that why my car boost is going up and down ?
ie : it try to hit 0.9 bar and then drop a bit and then try it hit it again ?
is it fuel cut ?
Do i need to change the fuel pump or injecter?
help?



My car had fitted : HKS evc , Apexi AFC , HKS air filter, full system exhuast , decat , boost set low 0.7 ,high 0.88.

thanks

Sounds simply like your boost controller is set up incorrectly.......I have posted a thread called boost spikes .......have a read!