Ben C34

Usual story man, pressure test to find a boost leak first. Search how to pressure test, it's the only good way to find boost leaks as looking at clamps etc doesn't cut it, and some leaks only occur with pressure in the system.

And just to add, I have both bsp and npt taps, so am completely certain is bsp. The npt tap does start, but after a couple of threads binds up, the bsp tap runs in nicely.

That's the obvious choice ti use a tee piece. but like I said, u need bsp npt is not the right size for the block. Alot of aftermarket stuff is npt cos that's what the yanks use, but the japanes use bsp. It is extremely close but not the same. If you have a search on here you'll find people have had issues with npt fittings.

Npt is close. But not identical.

I am 100 percent its bsp.

And the thread is 1/8 bsp if you decide to replace it.

Ecu doesn't use it.

yep

I have to disagree with that. I can't see how the turbo that's not bring driven enough by the exhaust would have any effect at idle. If you pulled the afm off a nice running car and took apart turbo system then put afm onto throttle body I bet it would idle fine.

This makes no sense.

Check everything you touched, as you must have done something cos you said it was fine before. No one is going to be able to pinpoint your problem for you over the net.

The imported for an old lady bit sounds suss

Ok. I am going to assume you changed the turbo, as swapping manifolds tends to suggest that. And as you didn't mention tune, I will assume that no tune was involved. My diagnosis, based on little info and taking a wild guess.... you killed the engine. (broken rings/ ringlands/ head gasket from pinging) Unless you have more info to add we can only guess.

I wouldn't think so. Surely issuing a scavenge pump on the return.

Nice. Does that manifold mount turbo in exactly stock location?

Search dude. plenty of info on what you are asking.

More info needed. But I would use a stock one.

Helicoils are heaps strong. You would have no probs.

Because Internet argument.

and the ground is dirty

con: doesn't fit

No benefits. What did you think it would do?

2 threads. same advice!

They are different options for a reason. Ring them and tell them what you want from a clutch, then buy the one they tell you to.

Could be heaps of things based on what you said. But no, not the ignition module.