ok so i got my rb turbo back system on about 2 weeks ago..this is on my 88 turbo II..and its been great..im running really rich to make sure i dont lean out. i ported my wastegate but apparently not enough because i still have a lot of boost creep even with my blitz ssbc(boost controller)..i see about 14-16 lbs in 4th...so i was running it pretty hard on the freeway just now.. and when i got off i noticed that my vacuum went from about -14 to -10...and my idle became shaky..i thought..vacuum leak for sure....i drove to my friends house...then wen i was coming home juss now it magically went away for a while..got to my house..it was gone but when i let it sit for about 30 seconds the vacuum goes back to -10 from -14.. if it is at -14 and i rev it and let the throttle go it will go back to -10...could this still eb a vacuum leak..because before it was at -10 all the time..and it would never go back to -14...ne ideas? bac might be clogged too because i have no cold start at all..wen i start it after 2 days sitting..it will still only go to 1500.. but back to the main question..could it be a dirty bac?" or should i start looking at all the vacuum lines..and is there a technique to narrow it down? i was thinkin soap and water..but vacuum, lines suck in not blow out..will it still work? sorry for the long post..
thanks for the help
dru

 

Spray come carb cleaner around the vac lines. The idle will shoot up a bit when a leak is detected. Check the IC hoses thoroughly...


The BAC can be OHM'd out to check for proper working order, the procedure is in the FSM.

 

Spend the couple of bucks for some starter fluid and spray around the intake ducts, the acv hose, the back of the throttle body, any and all blockoff plates and see if the rpms rise and fall. Also take a mere thirty minutes out of your busy day and remove the afm.....pull the duct b/t the afm and the turbo inlet off, and seriously look for a crack in that duct. In particular around the clamping area at the turbo.

 

ok i tried doign the starter spray method on almost all the vacuum lines viable without taking off the upper intake manifold and it didnt do anything..so i tried to adjust my bac..and with it totally tight..it seems to even out the idle..since i dotn like maxing anything out..i loosened it a bit..and adjusted my idle screw more rich...and it seems to have worked...u guys think it could be the dirty bac? ill probabaly carb clean my bac tomorrow..and let you guys know what happens