I searched about this a bunch after replacing countless hoses and lines. I even used a smoke machine and found no leaks. I read some where on this forum that the cams can jump while still having the correct number of links on the chain and cause low vac. Facing from the PS the cam on the left should be at 10 oclock and the other 12? Os this correct? BOV not opening/lots of backfire/plugs white and afrs never below 14.

JWT SER ECU programmed for 444s z32 maf 3bar fuel
145 compression across the board
draw through setup (needs to be recirced)
car hardly runs if not set at 20* timing
usually less than 10in/hg vac
HELP!

i posted this at night anyone?

did you adjust the ITBs (individual throttle bodies)

did you adjust the ITBs (individual throttle bodies)

no. should I?

How does the car run? I had low vacuum at idle because I was running pretty lean at idle. When I would adjust the mixture it would bring up (er, down) the vacuum to the 17ish range. Most Rs will idle between 16-18ish. If the car runs fine, I wouldn't worry too much about it. Also, keep your timing at 20*, it’s what it's supposed to be.

I do not have an adjustable fpr on it right now but i have a couple laying around at my dads house i will get. So your saying if I bump it up a little it will raise the vacuum? The car backfires alot on decel ppl think someones shooting at them.Under boost its dangerously lean high 13s low 14s. Also im running the BOV from the BB line and it does not open.

im kind of having the same issue. my gtir has a rough idle and the vacuum is bouncing btween 12-14. i just got the car so im gonna do a boos leak test but good luck with it, ill keep checkin in to see if someone helps you and me 2 lol

hah 12-14 is better off than me. I just cant understand it. ive done everything you can imagine to find a leak and there isnt one. And for this much vacuum loss there should be a giant leak. the engine itself is in excellent shape. Maybe one day I can actually enjoy it. im going to see what the vacuum reads NA.