Td42t instant boost loss

[Sweeting892]

Hey guys,

I'm a running an 18g/6cm kinugawa turbo with w2a intercooler on the td42 kettle.
When I put my foot down I boost to 7 psi then it drops down to nothing. It has a 14.7 psi spring in the actuator.
I removed the vacume line from the turbo to the actuator which in there should give me unlimited boost and the same problem arises.

I have checked all three hoses on the intake side and I've sprayed soapy water to see if that will show the leak but I've had no success.

Is bypass "flap" is the only place I drop that amount to boost that quick. No splits in the houses either. I'm out of ideas on what to test next.

[AB]

Have you checked the actuator arm is tensioned up, not loose?


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[Sweeting892]

Yeah it's as tight as it can be. When the actuator rod is disconnected It won't boost at all which is expected.

[Tip12345]

take the hose off and have a look at the comp wheel . then maybe the exhaust side . I have seen a few of those turbo fail in short time . and the little valve fall off the waste gate . it has not got to hot and melted the waste gate area !

[Tip12345]

Just had one in ate a nut !! and on disassembly had a waste gate melted the housing !!! only had 2000 km from being fitted so no one is putting there hand up !!

[AB]

Yep not uncommon for things to go wrong on newish turbos, trust me!

As above check inlet side for shaft play and take dump pipe off and inspect the wastegate is actually closed and check for tension there too.

Spring could've collapsed etc.


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[nissannewby]

Do you still have the pressure relief valve still in the intake manifold? Did you change anything and then the boost loss occurred? Or was it out of the blue?
Also check the line to the top of the fuel pump if no boost is getting to it then boost will suffer.

Also what type of boost controller are you running?

[Sweeting892]

No I haven't changed anything and yeah just our of the blue. There s no shaft play on the inlet. I'm yet to check the bypass for functionally. I'm making a home made smoker and to find the issue. I'm now realised that even if I hold it at a lower psi it starts to drop slowly and then drops to nothing again.

No controller. Direct to wastwgate with 14.7 psi spring