Integrals

OK my car has been running great since the rebuild, boosting a strong 10 8 10 for about 2 months and 2000 miles, but 4 days ago, it stopped building proper boost before the transition.

It now is boosting 3-4psi if WOT before the transition, and then drops 2psi and goes up to 10psi after the transition. If its not WOT, it builds no boost below the transition. I have already checked and replaced the Ypipe connector, the o-ring between the two Y pipe pieces, and checked the turbo outlet gaskets. All the 1" hoses are leak free and tight. All the I/C piping is new with new couplers and none have blown off or loosened.

My immediate thoughts are the Charge Control Valve/Actuator.

My brain is saying that if that valve isn't seperating the turbos during low RPM, all the boost will be vented via the CRV until the ECU closes the CRV at the transition, hence the recovery of 10psi immediately at that point.

Your thoughts?

zack4173

iTrader: (3)

For that much loss of air it sounds like a leak to me and a good sized one. What is you vaccum at when you are at idle?

Integrals

Vacuum at idle is 16-17in/Hg at 850-900 rpms

I just put a mityvac on the valve and it works properly. I also checked to see if the CCN was operating at idle by pulling the vacuum source on the CCV off while the car was running (valve opened) and plugging it back (valve shut) so it seems the Charge Control system should be working.

Again, went and test drove.. 5 to 6psi this time, and then 10psi at transition and went like a bat outta hell.

Also, i checked to see if the CCN opened the valve at 4500 freeload, which it did.


Ugh lol

Integrals

Geezuz, i cannot find the damn problem. The primary turbo should be pretty straight forward.. Vacuum on the CCV to isolate it, and then boost provided no boost leaks. Which I cannot find any, all the couplers and hoses and piping is new.

Integrals

Just did the Road test to confirm... 3-4psi and a loud whine (which continues up through the transition) on the primary, and full 10psi on the secondary.

I disconnected the primary turbine from the air filter to be sure it wasn't the inlet tube collapsing and no help there. Both the pressure and vacuum tanks are working well.

Integrals

Oh on another note, i was thinking, the two solenoids right under the pressure chamber... since they control boost, could i simply disconnect them, causing the turbos to run wastegate only pressure, to determine if it was a control issue or boost leak?

I also checked the plastic crossover pipe in water to see if any leaked through at the bracket area.. no go. looks fine

Integrals

Tried disconnecting the solenoids, 5-3-5 boost pattern then.

Still kinda makes a boost leaky sound but i cant find where the heck it'd be. I wonder if the HKS BOV is leaking. grrr, I dont have a stock one to swap in lol.

Anyones input would be great.

Integrals

Wow no one has any ideas? lol

zack4173

iTrader: (3)

Did you check to make sure the pills did not become loose and twist inside the vac lines?

cabaynes

iTrader: (4)

"A loud whine" - Does it sound like a police siren? If so that primary turbo could be dead. Did you check how well it was spinning by hand, or see if there was a lot of loose movement of the turbine shaft?

Integrals

Checked the pills, they are good to go. The primary turbo spins freely with little thrust. I had just checked them when rebuilding the engine.

Hmph. lol

Wonder if the BOV is leaking

Integrals

Pulled the UIM off and found the line to the ACV off. Dont think that woudl affect anything boost wise though? Idles fine strangely enough lol

Integrals

WOw. i feel retarded, I put it all together and fired it up, but forgot to connect TPS. Rev'd it (freerev) and watched the AF go nuts, shut it down, reset the ECU just in case and then started it again with the TPS plugged in. And rev'd it again. But my dumbass forgot that it had to relearn idle so I f'd up that process and now the fan kicks on and it shuts off lol. Gotta let it cool down again and then try this again.

The turbo though does spin slowly at idle. It may be worn out... spins quite well at 1100rpm.