This may be my problem also.

Pulled the manifold last weekend to install silicone intake and have had troubles all week.

Rough idle. Sometimes drops to stall at start-up.

Unplugged MAF and it does what's expected-so that's fine.

When I change gear above 4000-4500rpm the car drops acceleration completely for a second an then continues. E.g when accessing freeway.

Can only use 9 of 18 psi

Seems to run fine above idle to 4000rpm tho, so this is where I have been keeping it.

Sound the same ?

If so I'm off to the shop for o-rings today..