surging under boost

[TerminalVelocity]

ok, I have a RB20DET in my Z. I just changed my manifold and dump pipe. Before I did this, when I would up the boost to 12-15psi it would surge under boost and make a studdering noise and hardly move. Sometimes it wouldn't happen, or just for a bit of a second.

Now after the manifold change, it does it even on stock boost (10psi). I haven't checked the MAF yet, maybe it is that? It likes to backfire alot, although after the manifold change it hasn't very much.

I do not have an A/F guage. Nor do I have a FPR.

Got any ideas guys?

edit- I fiddled with my gain, and nothing changed.
I am running 91 in it (highest besides 100+ in CA).
Also, when I take it out of gear, it dips below 800rpm sometimes dying.

[tazdev]

take out and clean the AAC valve, that should fix the dropping revs, not sure on the other issue though

[TerminalVelocity]

well, I talked to Tat, and we decided that I have a missfire, and I realised my plugs wernt changed after the swap.

As he described it "its like hitting a mini rev limitor" also I noticed it missfiring at idle

anyway, where is the aac on the Rb motors?

[TerminalVelocity]

ok, I just checked my plugs, they were a lil dirty *from running rich and not being changed for....who the hell knows how long*

and they were gaped at about .043

I cleaned and regaped to .030 and it is running ALOT better.

Any other ideas to help make it run better? Like maby a different ignitor chip? Any cheep upgrades

Also I have some oil in the piping, thinking maby the turbo is slowly giving out. Do I have a T25 or a T28 on my RB20DET?

Any help is much needed!