OyvindRX-7

Hello.
Been trying to figure out of what could be a boost leak or issue w/my seq system.

Info on the car:
Stock turbos, engine, control system, PFC w/Datalogit, 3" Pettit DP, stock cat, airpump, 3" Blitz Nurspec CB, dual K&N intakes, Vmount kit. Full vac hose job and using DaleClarks check valves.

NOTE! I have bought new OEM hoses to the WG and precontrol actuators, the two with the pills in. (Is there any other hose with pills in?)

First of, the issue is that my primary won't boost more than 0,5 bar (roughly 7psi)
and the secondary I see "creep" like boost. After the "dip" it goes to 0,6 bar then erratic over to 0,7 (boost aimed for) then over to 0,8 when getting close to redline.
The car doesn't feel as fast as it should either. It doesn't go better than it did bone stock w/3"CB and I found out the stock ECU was EPROM chipped of some sort. And I would think the 3" DP, intakes and cooler would make it faster.

I thought it might be the PFC settings, so I have fiddled ALOT with these, adjusting boost and duty and over again, and final results is as told above. Before, the sec. boost would not go passed 0,65 bar. And the primary is and was at 0,5.

Then I have got a mityvac and tested all the actuators as per FSM (both precontrol act, WG act and turbo control) all found working as they should.
Along with these I also tested the charge relief valve and air bypass valve. WG and precontrol solenoids have also been tested and found OK.

Then I went on to checking for leaks. Got an air compressor, sealed off intakes on the turbos, hooked up the "air gun" to one of the unused nipples on the intake, took a mech boost gauge and tee'd the line to the air bypass valve so I could see what boost I got along with my dads 3 fingers placed on the various holes at the oil filler neck.

Then I found one leak, a tiny hole in the tig weld on my hot pipe, this being very small I can still feel with my hands that air is coming out. Is this enough to cause this?
I also hear a hissing sound from under the intake, (I'm applying approx 0,4 bar with the compressor) but when it drops, the hissing stops. Is there any of the solenoids that vents air when ign is off?

To summarize:
Low pri boost 0,5 bar/7psi. New hoses with pills.
Creep like boost after transition 0,6->0,7->0,8 near redline.
Found small leak in weld in hot pipe, enough to cause this?
Leak/hissing sound under intake when pressure is applied, when the pressure drops it stops.

Any input, or tips to solve this will be much appreciated.

danny hahn

pills, just 2.
hissing: since it's under your intakes I would bet its a solenoid not holding either pressure from the pressure chamber or a solenoid not holding vacuum from the vaccum chamber. there is a write up on testing solenoids which involves testing them out of your toaster oven with a pressure and vaccum hand pump.

not familiar with term hot pipe

OyvindRX-7

Well okay. But as there is a couple of solenoids that have vent tubes w/small filters on them I thought maybe some of them just stand open and vent w/ign off. But I guess the UIM has to come off again.

Btw, hot pipe or hot side pipe = pipe between turbo and ic.

danny hahn

an easier check if the hiss is from the pressure or vaccum chamber. after running the motor to get pressure and vacuum take a hose off of each chamber to release and see if hissing stops quickly.

consider using something like jb weld epoxy for hot pipe leak.

OyvindRX-7

Nevermind I think I have figured it out
Found 3 more leaks today.
1. The PCV valve, boost enters the oil filler.
2. One way check valve for the fuel purge system (baad leak, flow goes both ways, this has also caused the purge solenoid to crap out and leak as well.)
3. Out the secondary throttle axles (spelling?), this is what I'm most curious about... is there any tolerances on this? Didn't leak that bad but I heard it farted out air when I applied it. Is there anyone who has seen something like this before?

OyvindRX-7

Bringing this back up.. The things above is fixed, still same problem... if anything it's almost worse now. Is there any other place the air might escape? If the WG isn't properly shut, wouldn't it the act. rod be all rattley and loose?
Starting to think the turbos might be dead, allthough there are no in/out shaft play and no oil leakage from them.
Any input is appreciated.