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FLUCTUATING BOOST PRESSURE
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Old 05 Jul 2015, 10:19 AM   #1 (permalink)
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FLUCTUATING BOOST PRESSURE

Hi. My MY99 Type R usually wont boost above 0.5 bar, but on occasion, it coughs and then reaches 1.1 bar. It can run at normal pressure for some time or it can drop suddenly back to 0.5 after a very short time.
When it is running with the boost able to reach more normal levels, the car can "cough"/miss if I floor the accelerator at low to mid revs, but then it flies up to max revs without problem.
I did have trouble with my Forge DV sticking, so I blamed this even after cleaning it because the boost often seemed to work correctly after I played about with the DV. That was until I removed it and blanked the hose and still it only ran at 0.5 bar.
I changed the Boost Solenoid and the MAF sensor without any effect, checked all pipework, restrictor pill, connections, etc and then disconnected the wastegate feed, which allowed me to reach higher boost up to 1.5 bar with ease.
This seems to point to a boost control problem unless I'm missing something, but is the ECU the culprit or could it be something else.
The only mods are a full 3" decat system, front mount intercooler and a cone air filter. It's not had a re-map, but I can't see how this would cause intermittent boost problems.

Any suggestions would be appreciated.
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Old 05 Jul 2015, 12:48 PM   #2 (permalink)
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Re: FLUCTUATING BOOST PRESSURE

Quote:
Originally Posted by beejay820 View Post
Hi. My MY99 Type R usually wont boost above 0.5 bar, but on occasion, it coughs and then reaches 1.1 bar. It can run at normal pressure for some time or it can drop suddenly back to 0.5 after a very short time.
When it is running with the boost able to reach more normal levels, the car can "cough"/miss if I floor the accelerator at low to mid revs, but then it flies up to max revs without problem.
I did have trouble with my Forge DV sticking, so I blamed this even after cleaning it because the boost often seemed to work correctly after I played about with the DV. That was until I removed it and blanked the hose and still it only ran at 0.5 bar.
I changed the Boost Solenoid and the MAF sensor without any effect, checked all pipework, restrictor pill, connections, etc and then disconnected the wastegate feed, which allowed me to reach higher boost up to 1.5 bar with ease.
This seems to point to a boost control problem unless I'm missing something, but is the ECU the culprit or could it be something else.
The only mods are a full 3" decat system, front mount intercooler and a cone air filter. It's not had a re-map, but I can't see how this would cause intermittent boost problems.

Any suggestions would be appreciated.
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