missing under boost and high idle?

[THE_ARTIST_]

well i just got my car back after the 6 bolt swap and we were testing it out and it idles high 1500-2000 RPM but if i let it sit for a while it will go back down to 750-1000 RPM. anyone know why its doing that. but my real problem is when im going under boost it starts missing but under normal driving it does good other than the high idle. the car has a rebuilt 6 bolt, 1G big rods, ross pistons, stock 2G head, new NGK plugs and magnecore 10mm plug wires, 50 trim turbo, tial external wastegate, etc...(check mod list). it feals like there is a spark problem, the plugs have been gapped to 28. im still in the break-in period so im not pushing it hard. possibly be the coil pack?

 

[oldman]

Pressure test would be the logical place to start.

 

[THE_ARTIST_]

details please. thank you

 

[oldman]

details please. thank you

Intake pressure test, AKA boost leak test.

 

[THE_ARTIST_]

ok ive fixed the high idle with a little tuning and such, but its still missing under boost. at about 10psi it starts missing and the car wont go anywhere, it was doing this before my 7 bolt broke. i remimber that it was running fine then i changed the valve cover and i went for a drive and it started missing at around 10psi (T-25). i dont know what could/can happen when changing valve covers but i remimber that it started missing right after i changed it, could the PCV valve be the problem? i thought it was the plug wires but i have new wires and plugs... very confused right now. will try a leak test ASAP

edit: it will rev like its souposed too as long as its not under pressure,

 

[oldman]

could the PCV valve be the problem?

Could be and a leak test will pick that up.

 

[THE_ARTIST_]

got it fixed, changed the PCV valve also did a little tuning (leaned it out up top), and i had a 1/2" slit in the coupler connecting the 90* elbow to the turbo, replaced with silicone coupler