Issue When vehicle gets hot
 

2009 Volvo C30 Diesel 2litre, owned for a few months. Have a problem, only when vehicle gets to temperature, when vehicle is cold drives absolutely fine no major issues. Once vehicle gets hot I have this issue at 3000rpm with about half throttle, feels like/ sounds like turbo is cutting in and out. It will boost and then open waste gate. But while it’s doing that, if you full throttle it, it clears and is fine but then will happen again. Have changed a lot of components tying to solve this issue. Including, Injectors (been replaced with a fully functioning car) Map Sensor, Boost Sensor, EGR is blanked (mapped out) also had sensors tested while vehicle running and everything seems fine. Fuel pressure seems fine (fuel pressure sensor been replaced, trying to eliminate things) apparently suffer from throttle body’s also been replaced with a fully function car and also has had a brand new turbo. Simple things like fuel filter, oil filter have also been done. Have also tried another PCM. After all this fault is still there. Wondering if any of you guys have a solution or can help. Thanks.

SInce this happens when the car warms up, I'd suggest you get a full scan with run time data to see if a tech can capture when the run data starts to go out. Also,
did you test the ECT (temp sensor)? I'd also check for air leaks and tubing. Theory is, as the tubing heats up, it gets softer and can open up a leak. You may want to do a smoke test. Also inspect wiring / clean connectors.