Missing Boost
 

Been outside the US for the last 2 months, drove to work today and the car only makes 4 PSI. Looked at all the clamps, all good, I'm thinking the BOV could be opening?

Any ideas? I'll look under the car at the discharge to intercooler stuff later this week.

Could my PS cooler have rubbed a hole in the intercooler? It Looks Very Close!!! OUCH!!!??? JB Weld...

Thought it might be a bad Vac/Boost sending unit, still may me but the vacuum readings look good.

Still seem to run good, I'll log some data on the way home tonight and check the A/F ratios. should be way rich if there is a leak.

Thanks

First try checking your bypass valve and see if it needs to be cleaned and lubricated. I've had similar issues in the past.

change the BPV, if that fixes it, then you solved your problem, if it doesnt then check the intercooler where you patched the hole and do a boost leak test and see if it is leaking from there(you can usually feel the leak if its really bad) switch the intercooler, if it isnt then you might need to tighten down clamps around all the silicone sleves

What lube did you use?

Adjusted my BOV and now I have 7PSI, It's leaking and I am so HAPPY it just the valve. Thank for all the help.

OK, when cleaning of my BOV it looks like someone put the a ultra-heavy spring in the valve and when it could not be opened by vaccuum he cut it down.

I bought this kit used from a 370z sponsor, not GTM, a very big mistake I might add, $1500 worth!!!! It was for a G37 and not a 370z.....

Just get a new one. Maybe HKS, GFB, or turbo smart.

I use GFB respons on my turbo eclipse and it holds all the boost I throw at it. Plus it was cheap, $200

New one is onthe way. The fix for now was Ace hadware springs. After the new spring install the valve is half-way open at idle. Under full boost it sould be full open from the SC pressure and the high vaccuum. At cruse it should be full closed. It should closer sooner as it is only part open at 15-18 inches of vaccuum. The old valve has never held up to full 1.5 SC boost. It will be fun to see if my new setup can handle 10PSI.

Sorry to hear about the issues you had with your bpv. The lube I used for my bpv was from TurboSmart and can be found here:

TurboSmart Multi-Spray

You may want to check the bpv at least every six months because mine was dirty and it needed some lubrication!!

Did you buy it from this website?
I have been trying to get this stuff, but everyone website I end up on looks shady.

Street Unit is legit. They're pretty much the go-to source for all things Mazdaspeed.

You can buy with confidence from them.

Excellent, thanks.

It should be open at idle,closed when you floor it and it will flutter under part throttle cruise.

It is open 1/2 at idel with 17 inchs of vaccuum. When I tested it with my vaccuum pump it was bypassing so much I could not generate enough suction to pull it open using my standard brake vaccuum bleeder hand pump. New one is on the way, tomorrow??? maybe today???

Hmm. My understanding of such things from my experience with my various F.I. cars, is that the BOV should be closed at all times, except when there is a pressure differential between the intake manifold and cold pipe, meaning the TB is closed but there's still boost in the cold pipe(s).

If it were open at idle, and you ran an un-recirculated BOV, you'd be sucking unfiltered and unmetered atmospheric air at idle...

I could be completely wrong though. Wouldn't be the first or last time.