The shop itself have only worked on the car. They replaced everything from a full hose job, to silinoids, to actuators, to nipples, spark plugs, earth wires etc. I spent around 900 dollers to have the owner Pete tell me he couldnt fix the initial problem i brought it in for the secondary boost loss. I have the list of things they replaced on my car its ridiculous. I myself would love to run some tests besides a boost pattern which i will probably run later today. I am happy to hear and am keeping my hopes up that the cat might be clogged. The owner Pete of the shop said the midpipe usually if clogged wont cause a boost problem but then again he wants me to go ahead and do a full rebuild. But I do feel my midpipe is causing the problem, at idle if i tap the gas i get backfire not flames but popping noise. The car pops everytime i tap the gas even if its only to around 1 thousand rpms.

 

What shop?

 

PBC Automotive

 

Ok, a friend of mine just informed me that the poping/backfireing is normal because the system allows it to run rich during cold weather.

 

I took my car to PBC Automotive (the one in chantilly right?) for a similar secondary boost problem a couple months ago, my boost was higher than yours on the secondary but dropped similarly.

They basically looked it over and said everything was cool, my secondary turbo was fine, but to debug the slight leak would cost more than I wanted to pay. They were right that I didn't want to pay them, so after enough hints from people on this forum I finally found it was my y-pipe that wasn't bolted onto the outlet of the secondary properly. Primary worked fine but probably leaked a little, the secondary leaked enough to lose boost and created a loud whistle. One bolt and everything is now perfect.

For the record, I don't blame the shop. I've had the car at dealers and shops in california for the last four years trying to find the problem. None of them found such a simple problem that I would guess was caused during the install of a rebuilt engine.

Not sure if that helps, but I'd definetly say take everything they say with a grain of salt and learn how to fix it yourself. Unless you have money to burn...

 

I never dealt with PBC. If Farrell was open I would tell you to take it there for a second opinion but I'm pretty sure he is closed.

I know others have told you this already but be sure it's not a hose. Check it with the diagram before you get into the bucks involved with turbo replacement. All these more complicated explanations for a lack of boost usually end up being a hose or a solenoid.

Do you know anybody with an RX7 that you could compare side by side to check the vacuum hoses? It's easy to screw them up.

 

Assuming that your cat is not clogged,
Your boost pattern SUGGESTS that perhaps the flapdoor inside the y-pipe is not opening to allow the 2ndary boost to come online, and the primary just runs out of breath as revs climb.
If the boost had just plummetted to zero, then it would've likely been the CRV stuck open.

IF you have a boost gauge, then you might be able to do a test whereby you rig the flapdoor open and disconnect the CRV...I understand this to be part of the non-sequential conversion...but you would have to closely monitor your boost gauge.
This may tell you if you indeed can get boost above transition, and hence that your 2ndary turbo is working.

I have NOT done this (I have other similar 2ndary issues) and would hope for some input from the gurus here, either yay or nay, because I do not want to give you bad advice. Seems to me it would answer some questions, though.

 

Yeah I still insist that there is something wrong with the y-pipe on the secondary side or the crv is a good possiblity also.

 

wow you guys, now you got me thinking that it could really be the Y pipe. Because they replaced everything from a full hose job, to solenoids, to actuators and cvr, to nipples, spark plugs, earth wires...

I am eliminating that it is my mid pipe cat, and I have a hks dp so its not the other cat. I really do think the Y pipe is a good guess. How hard is it to get to the Y pipe and check it. I am willing to embark on this journey if its not too difficult.

I will be scanning a copy of the work PBC did and posting it here ASAP!

 

It's right in front of you as you stand on the passenger side and remove the air hoses. A replacement half that includes the valve is very cheap on the classified board.

Remove the two vacuum lines that lead to the actuator, and move the arm with your finger. It shouldn't take more than several ounces of force to move the spring, and it should snap back. If you have a vacuum/pressure test pump (a Mityvac), test it per the FSM procedure. Make sure it doesn't leak from one line of the actuator out to the other. On mine, the actuator seemed fine, but the valve was gunked up and moved slowly. I removed the y-pipe, took apart the valve and valve arm, and cleaned and regreased it. Nice and snappy again, cost = 0$. Just be sure that when you reassemble the door you have it in the same orientation as before.

Also, there is an o-ring between the y-pipe halves, pick up a replacement for that too. But that wouldn't affect secondary boost as it's exposed to primary boost too.

Dave

 

Thanks man, I am going to go take a quick look at the Y pipe.

Here is a copy of the invoice for all the parts that were replaced.

 

Sounds like a reasonable shop.

Don't get too excited about the y-pipe....you could still have a sick 2ndary turbo. But checking the y-pipe and the flapdoor will answer some questions.

It's very easy to get to and to disassemble. Make certain you have your long needlenose pliers. Good opportunity for cleaning, lubricating, even painting.

 

Yeahm there service is nice, I just wish they could have fixed the problem. They gave us a break on the price, it all came out to $750.

I will not be exited until me and my cousin get the car running how it should be. But what I plan on doing is calling PBC tomorrow morning and asking them what they think about the Y pipe, if they say it might be the problem then I will take it in and have them check it out.

 

I just got off the phone with PBC and they told me that they never checked the Y Pipe. I think I am going to have them take a look at it. I would do it my self but dont want to take the chance of missing something up.

 

Is there a good driving test for the second turbo?
I get a real kick in the *** when the first turbo engages around 3500,
but it doesn't seem to surge when second turbo should kick in around 5000.
Keeps running strong, but no surge. Owner of turbos before turbo rebuild indicated there had been problems with the second turbo not engaging.

If I hang the RPM around the 5000, there is some noticable oscillation with slight throttling up and down. Would intentionally doing that help keep the actuators limbered up?

And no, I do not now have guages for boost...

 

Letting off/on above 4500rpm will cause noticeable lag since you're reengaging both turbos at once. But if you let off at 5k, and get back on hard again at 5k, you should only feel that one pause, no oscillations.

Get the boost gauge, even if it's just a generic pressure gauge and some tubing to get you a diagnostic reading. It's square one as far as diagnosing this.

Dave

 

my primary seems to dissapear somtimes... usually for only a few minuites and very rarely. Rotary Preformance wasnt able to diagnose it either.