hi there, i am new to this great forum.

i have a 93 fd, current mods:

apex twin intake
power fc w/ base map
custom 3" cat back
greedy turbo timer
RE carbon fiber hood

i have problems with boost pattern, both before the power fc and after.

i get boost from the 2nd turbo half of the time. every time i don't have boost, after i left off the gas, i hear leaking air from under the hood( not the blow off valve sound!)
if I get good boost , i don't hear that sound.
This problem occurs more with the power fc installed.
any guru can help me??

 

My problem was with the rubber hose that connects the y pipe to the long black plastic pipe that goes over the engine to the intercooler. The clamp kept slipping off the lower end of the rubber hose. My brother had a leak in the same place. If that's not it try this thread.

 

Well, your symptom is pretty vague..
You need to tell us what boost you see.

But maybe this will help..

Most of the primary boost lost I have seen is leak on the IC piping, couplers.. I would check all your couplers and hoses for crack and leak.. And also the BOV rubber line and where it attatches..

When you don't build 7lb of boost or higher, your secondary turbo will not kick in.. so, primary turbo must be fixed.. If some reason you are getting strong 2nd but no primary.. than its something to do with your pre-spool or waste gate control.. or like my case, it could be your boost controller.. like AVC-R.

If you are getting good primary and no secondary or tempermental secondary.. check your check valves.. or oneway valves.. those get clogged and pressure or vacuume does not build.. which needed to open the charge actuator by the y pipe.. If the flap doesn't open all the way secondary spool will not come thru the IC..

Also check your PFC boost setting.. PFC also controls boost.

 

THANKS ALOT GUYS,
I JUST FIXED IT THIS MORNING BY REPLACING THE ONE WAY VALVE IN FRONT OF THE INTAKE MANIFOLD, THE CAR RUNS GREAT NOW. I AM GETTING THE BOOST GAUGE SOON SO I WILL CHECK MY BOOST PATTERN. THE VALVE WAS $29 FROM THE DEALER, HOPE THIS COULD A FEW PEOPLE WITH SIMILAR PROBLEMS.

 

Good to hear that everything worked out..

also you could use one way valves from T2 or any other one way valves.. long as air flows one direction..