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Boost control issue.

shadows672
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shadows672 Rookie

shadows672

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So I've had my R33 for a few months now and I've recently been having boost control issues. I have Greddy profec B Spec II and its acting very strangely. It drives fine and holds boost until it hits peak boost (14psi) then it will no longer make any boost. The display says it's making around 1psi. But then after leaving it for a while it will work fine again, rinse and repeat. Is it the solenoid sticking open? Any help would be great. 

Cheers 

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admS15 Grand Master

admS15

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Well if it works fine with the boost controller unpowered then the issue definitely lies there. The thing is, if it's switched off, the lowest the boost can go is wastegate spring pressure and i would expect that to be between 5-7 psi. You said when it plays up your only getting 1 psi. Since you have an aftermarket split dump, i would definitely check the flapper opens and closes smoothly and doesn't get caught open. Some of the split dumps have a reputation for causing this. Wont take long to check and rule it out as a possibility if it's all good. Cheers.

admS15 Grand Master

admS15

Posted
Posted

You're going to have to determine why it's sticky. Most probably it is fouling the inside edge of the dump pipe. You will have to take the dump off to take a look and either dremel it for clearance or replace it with a bell mouth dump. The other possibility is the flapper mechanism itself is faulty and sliding in and out. Pull the dump, diagnose and then take action. Cheers.

admS15 Grand Master

admS15

Posted
Posted

No probs. You could also try spraying some wd40 or similar on the shaft of the flapper and open and close it quite a few times and see if that frees it up before you go pulling shit off. I use to have a turbo on an old car of mine that had a sticky gate and doing that would remedy it for a few months. Give it a shot, can't hurt. Good luck

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