Herblenny

iTrader: (13)

I need some advice..

So, I was having secondary turbo issue..

My original symptom started off my secondary turbo hesitation.. Almost like an ingnition break up.. So, I changed the plugs, check the wires, etc.. still 4500+ break up..

Then It was combination of break up and this whistling sound.. which sounded like something was open and I could here the turbos spinning..

Then I started to notice that when My secondary turbo kicks in my boost level dropped..

So, I thought is was the vacuum issue.
I took everything off and did the simplified seq. turbo mod.. Got rid of most of the rats nest and solonoids..

Tonight, i took the car out and everything seems to be o.k... So, I took it out on the interstate to do some pulls 3rd and 4th gear..

my primary turbo hit 0.8 bar with out problem.. as RPM climb and secondary is supposed to kick it.. I see my boost starts to drop.. At 6K.. I was at 0.2 bar..

Also, it made some weird noise.. but not as that high pitch whistling noise..

Anyhow, IF you have any suggestion, ie, what to look for or something, please let me know..

Thanks so much!

PHIL SOHN

93BlackFD

sounds like your turbines are hitting the compressor housings....i'd take it to BNR and let them inspect the turbos themselves....or....keep playing with the sequential stuff until you're fed up, then go non seq

Mahjik

iTrader: (1)

Are you still running a cat? If so, it might be clogged. Just a thought.

Railgun

I've had a clogged cat before (badly). I would think that he'd have performance problems across the entire RPM range.

Could it be boost leak in such a way that the opening is whistling, so he's not hearing the typical woosh of air? Or maybe a cracked housing?

half past twelve

Check the intercooler/ypipe coupling?

Herblenny

iTrader: (13)

Here are my mods.. stock IC.. PFC, intake, apexi bov, dp, mp, cat back..

I'm also getting ready to put on fmic.

My couplers are fine.. I had efini y but now I'm using stock 93 y-pipe (I'm polishing the efini y).. but I checked for cracks and leaks.. I also had this problem w/ efini y..

And i think my secondary turbo is o.k.. I feel like somewhere in between secondary turbo and the y-pipe.. I'm going to check the bov..

Mahjik

iTrader: (1)

Actually most people only notice the performance problem of a clogged cat as it starts with the secondary boost (after 4500 rpms) when there is more exhaust flow. However, he has a midpipe.

I would take a look at the CRV and/or the hoses to it.

ExpensiveHobby22

Are you saying your couplers are fine or have you checked? You should take them off and actually check if you hadn't. They can look fine, but have cracks that spread when under boost, especially under the hose clamps where you can't see them.

Also check the 1" hose that comes off the second turbo to the CRV. I had the exact sypmtoms you are talking about and that hose had popped off where it meets the turbo. A friend of mine also had the same symptoms, but nothing was obviously wrong. It turned out that the whole back side of that hose where it meets the turbo had disentegrated.

-ray

Herblenny

iTrader: (13)

I'm going to check the CRV when I get home tonight..

I don't think its the couplers, since if its the couplers, I wouldn't just have problems at secondary boost.. My guess is the 1" hose.. I do remember being slightly loose.. I'm going to go head and replace it tonight..

Thanks again guys.. This is why I love this forum!! Make me think!

PHIL

911GT2

I hate to say it man, but that sounds exactly like my symptoms when I had a blown secondary. Good primary boost, then boost just drops slowly to redline, with a griding sound accompanying the secondary turbo. Not good news...

Herblenny

iTrader: (13)

I got home early from work so I could check the CRV.. I checked it and its fine.. And I replaced the hose also..

I just went out for a drive.. and still really bad..

One more thing.. Could this be because I have heat soaking problem??

I have SR PFC with IC, intake, full exhaust map.. I had PFS ic and intake but had to sell it because my new hood did not fit.. So, until my FMIC, i been running stock IC.. But I just can't believe its because of IC..

I'm going to take it apart and re do the vacuum lines with thicker hoses.. Maybe my silicone lines collapsing.. I did hear some weird hose sucking noise this time..

PHIL

Herblenny

iTrader: (13)

damn.. that wouldn't be good.. I have always felt that my secondary was better than my primary.. until now.. I do have another set of turbo that I could put in.. but i was saving it until I rebuilt my spare engine..

FEARED7

Hey Phillip! convert that stuff to non sequential! No more creep in transition and it will have more predictable boost patterns. Bring your manifold/Y pipe to me and I will gut em for ya...

Bryan
www.bnrsupercars.com

Herblenny

iTrader: (13)

I like the seq. turbos.. I'm going to try one more time.. If it fails.. I'm bringing it to you Bryan..

Oh.. do you think i could buy some vacuum lines from you?? It might be that mine are too soft..

Wade

iTrader: (1)

herblenny,

I think you need to do some real troubleshooting. You likely have a leaking check valve or solenoid. You'll need to be more descriptive of your boost pattern before anyone can really help you more.

Offhand it sounds like a turbo control solenoid problem. A local guy was only getting 5 psi on the secondary turbo and his turbo control solenoid on the pressure side was leaking. T into the pressure chamber and vacuum chamber and monitor the press/vac all the way through the revs and report back. That should help narrow the problem down.

Wade

Herblenny

iTrader: (13)

Thanks Wade,

Tonight or tomorrow morning, I'm going to re do and check all the solenoids.. And I'm going to replace the vacuum line with thicker rubber kind of hoses.. I think my silicones might be collapsing.. I'm going to try it one more time and I will take video or something and report back.. I hope to get this thing worked out..

Thanks again everyone for your help..

PHIL

Herblenny

iTrader: (13)

Ok.. I checked all the vacuum lines tonight and they look and feels o.k.. I even checked the solenoids... Everything looks o.k.. I'll test it tomorrow..

Also, i forgot to mention that I have AVC-R.. and I read somewhere that some people had secondary boost problem... Hmm.. could this be it??? i don't know how to check it.. and the whole thing about "T"ing pre spool and waste gate thing.. I dont quite understand it..

Herblenny

iTrader: (13)

I just read this thread and it was very informative..

http://www.autosportracetech.com/RX-...leshooting.htm

And i think i figured out why.. I'm going to test it tomorrow.. make sure if everything works out or not..

I left one of the one way valves off.. From y pipe to the pressure chamber.. Now I think about it and i think thats why I was hearing the leaking sound or something weird during transition.. And I also found out that some of my one way valves were in pretty bad shape.. no air could go thru either direction or hard to pass air thru.. The one on the y pipe to the pressure chamber is slightly hard to pass air thru.. i might pick new one from auto store or Mazda dealer..

PHIL

Herblenny

iTrader: (13)

Problem Solved..

First I would like to thank everyone for posting on this thread.. you guys have been great help..

Far as my problem goes.. And hope it might help others in the future..

It was the one way valves..
I first checked all the solenoids and they seems to all click (just hook it up to the 12V battery).

than I checked all the lines for splits and leaks.. NON were found..

Than I read the link above about troubleshooting turbos and read about the one way valves (black/ green and white/green)... I took them off and blew on it.. and first one did ok.. but some restriction.. Then I checked my line from y-pipe to the pressure chamber and there wasn't a valve.. I guess I forgot to put one on.. So, I checked the other 3 one way valves... and to my surprise, one one flowed freely and other two were completely blocked.. or very very restrictive.. So, i think this is why I was having turbo issue in the past and after the simplification..

I took the car for a spin and at 45MPH kick on third, it ran like a champ!! all the way to .85 bar (that's what my PFC was set, and AVC-R showed .95 bar.. but I have seen difference between AVC-R and PFC.. I'm putting a Greddy Elect. Boost gauge in a month or so..)

Mahjik

iTrader: (1)

Great news! And thanks for updating the thread with your resolution.

Herblenny

iTrader: (13)

Not a problem.. I am so happy that it wasn't the turbos..