I know that this topic has probably been beaten to death on the forums already, but after reading about 30 other boost problem threads and running through about 38 hours of trouble-shooting on my problem with no fix thus far (for better or worse) I have to call in for help.

Basically here is the problem...Was racing through the mountains one night and noticed that the car sounded funny. It drove fine, but there was a lack of power, so I noticed that I had no boost all the sudden. Gauge reads at about a steady .4 bar in all RPM ranges from 3000-redline. There is a distinct rushing air sound like all my boost is being vented out. I suspected a blown line or something, but after tearing the car apart and inspecting all the lines and such, I haven't discovered anything broken or cracked/split. I did adjust and tighten some claps thinking that was the prob, but no change. The boost pattern test gets me 5 5 5 5 pretty much across the board. I pulled the connectors on the WG and Pre-Control solenoids trying to see if I could get at least 7psi out of the car, thinking that it might be and ECU problem, but no good, still only made maybe 5psi. I've switched the ABV and CRV thinking that It might have been one of the two leaking pressure, no change.

The car is a 92 FD3S Efini edition, running stock twins, only relevant mods might be the the Apexi intake, and full 3" turbo-back exhaust, the secondary throttle control has been removed also, everything else is pretty much a stock turbo system.

I'm becoming very frustrated with this...please help!

 

Turbo Control Actuator?

 

Have you looked at the CCA/CCV? Check all the lines there as well as your 1 way check valves to ensure they work correctly. If the CCA/CCV is sticking it can vent your boost out the CRV.

The primary turbo has to be working first, so concentrate troubleshooting in that area.

Here's a good link to a turbo troubleshooting site: http://se3p.com/index.php?title=FD3S...roubleshooting

Edit: Get a Mityvac silverline plus...invaluable for turbo troubleshooting

 

Make you one of these

http://www.supramania.com/forums/showthread.php?t=19718

 

I have the same setup. But a rb dual tip with PFC. Today I'm feeling the same thing of boost loss. Only boosting 0.4bar. If you fix the problem. I whould be happy to know how u did it

 

There is a good chance that the rubber boot on the y-pipe to crossover tube is cracked. It is very difficult to see. Take it off. Bend it, twist it, and make sure it has no cracks.

 

Okay, after much deliberation, I broke down and ripped every freaking hose out for the 5th time and went over all of them with a fine tooth comb and a magnifying glass and found a split Y-Pipe coupler (good troubleshoot adam c!) and a few lines that had hairline splits that you cant see unless you physically raped the hoses. I'm currently waiting on parts to replace them all, so I'll keep you all up to date as if it fixes the problem or not. Thanx for the help guys!

 

nice.. looks like i gota do the same dam thing then. LOL

oh btw does your apexi intake bottom piping dont fit snug?

the one that goes to the turbo ?

my coupler wont fit snug and there is no play room to make it fit right

 

Looks as if the split coupler was the problem! Hell yeah! Got my boost back to standards! Thanx for the help all!I think it's time I just trash all that stupid factory hosing anyway and get aluminum piping.

Both my intakes fit good, I'm using the stock rubber hoses that came with the car for the intakes, it's just the filters and their respective holders that are aftermarket so the hoses fit like factory where they mount up to the turbos themselves...if that answers your question.