puma

iTrader: (2)

OK guys, I need to see who is a boost champion here

I just did a hose job on someone's car, removed all the emission stuff. Before i started, the car had boost problem, couldn't get more than 4 PSI.

Now that i have done the job, i still can't get 10 PSI on the first turbo, but i do on the second.

There are only 6 solenoids left.

I know it can't be the wastegate and turbo precontrol since they have nothing to do with the primary.

It is not the charge control and the charge relief valve either.

So the only thing left are the two turbo control solenoid, one for the pressure and one for the vaccum. Could one that goes bad make this kind of problem? I though it would only make the boost build up slower if it was one of these that went wrong.

I checked every actuator and they are well hooked up, I also know it is not a boost leak.

What do you guys think, anything else might be possible other than a blown primary turbo? I really do beleive it is a blown primary but anything else before i send them to a rebuilt?

thanks a lot

puma

JONSKI

Low primary boost can be caused by:
Charge Control Actuator not closing far enough
Damaged turbo
Wastegate opening early


Before you send it off, take the primary turbo inlet off and inpect the compressor wheel visually. Check for things like damage due to contact with the compressor housing and chipped edges. Then check for shaft play by gently pushing the wheel side to side. It will move about a millimeter in either direction, but it should not be able to contact the housing. Gently pull and push the wheel and make sure that it has no front to back shaft play. Finally turn the wheel with your finger. You won't be able to spin it like a top, but as you slowly turn it make sure it feels smooth and not "gritty" or "sandy".

puma

iTrader: (2)

yeah, i checked the turbo from the inlet, shaft play seemed like it was OK although there was some of it, more than a mm.

having the wategate opening early, wouldn't it cause some problem with the sencondary turbo either?

and as far as the charge control actuator, any way to check this?

thanks a lot

JONSKI

The best way to check it would probably be to disconnect the charge elbow from the secondary turbo and y-pipe and then operating the valve by hand and making sure it is not sticking partially open. When the Charge Control Valve closes it does not form a complete seal by any means, but it should be closed enough to prevent low primary boost. I really doubt it, but you may need to adjust the stopper screw for your CCA. I immagine the you could probably operate the actuator by sucking on the larger vacuum hose as well.

johnchabin

iTrader: (2)

Make sure the Turbo Precontrol Valve is fully closed by moving the Turbo Precontrol Actuator in and out when the car is not running. It should not feel loose - there should be a bit of tension pulling the Valve shut.

SleepR1

I don't mean to high-jack this thread, but since there are so many boost problem threads already, I thought, I'd dove-tail my problem here.

My turbos are J-spec twins. They're only 9 months old with ~9500 miles on them.

The primary makes 7-8 psi, and at switchover, the secondary and primary make no more than 3-4 psi.

I've checked many things, but have not checked the secondary turbo's shaft play, as was suggested.

Brief WOT to redline in neutral does NOT make 4 psi like it's supposed to. The boost gauge reads atmospheric (0 boost) in neutral @ WOT to redline. This apparently signifies a boost leak somewhere.

Checked the precontrol and wastegate rod lengths. They are adjusted properly, and the wastegate and precontrol doors are shut with the motor off.

Air bypass and CRVs are both new.

Wastegate and precontrol solenoids are new.

TCA and solenoid are new.

New check valves for the pressure chamber and vacuum chamber.

New chambers (pressure and vacuum).

1-inch diameter hoses are screw clamped in place.

GReddy FMIC and Airinx all come with hard pipes, and silicone couplers...all are tight.

Checked double-throttle control, and it's working properly.

Charge control actuator rod is pushed in when motor is running, but releases when you cut off the motor. Not sure if the CCA rod is supposed to be in when the motor is shut off...most everyone's releases, so...

I bought the turbos brand new from SR Motorsports last Fall. I'd be shocked if the secondary or primary turbos are shot being so new!? I've submitted a warranty claim with SR Motorsports. We'll see if they honor it...

SleepR1

Haven't tried this. How how hard is it to get to the CCA elbow?

JONSKI

You need to remove the rear turbo inlet and a few plastic air pipes.

SleepR1

Checked the shaft play on my secondary turbo. There is some, but not an unusually high amount of radial play. The secondary turbo compressor wheel turns between my finger tips without much resistance. I can't really say the J-spec turbos are bad at this point. I did snug down the lower 10-mm flange bolt on the CCA/Efini Y-pipe elbow. No change in my boost pattern though...still 8-0-4 psi...

SleepR1

Awaiting a response from Greg of SR Motorsports on whether Mazda offers a warranty on their '99 Japan Spec twins. As mentioned above, I'm not entirely sure the twins are bad. It could still be a turbo control issue at this point. I'm at an impasse. The only actuator I haven't replaced is the CCA.