Miata stops making boost around 5000rpm
So i've randomly encountered a strange issue that i need some help identifying. So the car ( 1.8 turbo with mspnp2, stock engine) pulls hard up to around 5000 or so RPM and just loses all boost pressure, it makes a very quiet sound similar to compressor surge. Im not running a BOV at the moment but i wasn't having the issue before i put on a boost controller. I've tried running with wastegate pressure and get the same noise. Any ideas would be greatly appreciated, thanks!
Ok so i did a few pulls and got it to happen once in this log, it happened right after the first mark i placed. The car has no cats, 3in exhaust, no boost leaks. I'll be installing a BOV when it arrives to see if that could be the difference but i don't think it's the cause.
Ok so i did a few pulls and got it to happen once in this log, it happened right after the first mark i placed. The car has no cats, 3in exhaust, no boost leaks. I'll be installing a BOV when it arrives to see if that could be the difference but i don't think it's the cause.
Ok I think i figured it out. My o2 sensor died yesterday so i replaced it with a new one and my afrs must have been messed up. Going over that log looks like I'm lean in boost so I'm going to make some changes and hopefully it'll be good.
what turbo/Wastegate setup so you have? Maybe Wastegate blowing wide open under high rpm boost?
Last edited by borka; Jul 14, 2018 at 12:33 AM.
Ok so i made a couple changes and i'm still getting the same issue. I have a great datalog of the issue occuring twice. I tried stayed on the throttle so you can see boost falling off and the car just loses power. I really have no idea what it could be because its not making any crazy noises, it just stops making boost. Turbo is a china t28 with ebay wastegate. Could my turbo be shot?
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