2nd Turbo Problems

[nikp]

Well, for a while now i\'ve suspected that \'something\' has been not right about the power delivery on the 2nd turbo. I finally got around to installing my boost gauge yesterday, so I could actually identify whether it\'s boosting correctly.

The results were interesting!

Firstly, on idle the gauge read -0.4 bar. Is this correct?

Then, on the first turbo it certainly seemed to created 0.8, then on transition it dropped to 0.5. Then the curious readings occurred! (It was dificult to get definate results, as I couldn\'t stay on the 2nd turbo for long as I kept catching up with traffic!! :p )

But we seem to think that the gauge read momentarily 0.8 on the second turbo, then dropped down to basically nothing. Sometimes around the 0.2 mark, but certainly not a consistent 0.8

Can anyone offer any advice and/or suggestions as to what the problem might be. I wonder whether it\'s just as simple as a boost leak in some of the piping, but my bro\' suggested it could be something like a wastegaste. Any help appreciated!!

[Shaq]

i had the same problem on the second turbo, it was the vacuum  line going into this some kind of vacuum box under the strut brace(black in colour) there are 2 vacuum line connected to this i found one of them had poped off just replaced it with some samco stuff...... failing that........

 check the Coupling which is connected to the y-pipe sometimes this has a slight rip on them
i will try and sort out a pic

Check this out:


http://www.autosportracetech.com/RX-7/TurboTroubleshooting.htm



ShaQ

[Shaq]

just remembered a friend of mine had this problem too check this thread out this 90% sure this should fix your prob..


http://www.mazdarotaryclub.com/forums/showthread.php?s=&threadid=2375&highlight=boost+leak



shaQ

[nikp]

Cheers. I\'ll take the plastic pipes off this week, and inspect them for signs of cracks and/or damage. Hopefully, this will prove to be the problem, and I\'ll be able to fix the bugger!! :p

[nikp]

To anyone who is interested!:

I took the major induction hoses off last night to inspect the condition of them for cracks or damage (or both!). And, unfortunately couldn\'t find any signs of damage.

I know that the induction pipe to the first turbo can collapse under high rpm sometimes, so inspected that in relation to that too. The only thing I could spot was that on one of the \'ribs\' near to where it bolts onto the turbo it has \'buckled\' into itself - now I\'m wondering whether this is a sign of it collapsing. This buckle has been there for so long, that it is more natural for the plastic to be buckled, than not to be.....I hope all this waffle makes sense!!

Obviously a picture would make more sense, but I don\'t have a camera on me at the mo!

[iaint]

It\'s most likely that it\'s a vacuum host that\'s split or collapsing or possibly one of the solenoids.  I had exactly this problem before rebuild and one ofthe solenoids was sick.

the -ive boost on idle is normal.  If you watch it when you come off the gas and coast it\'ll drop to close to -1 bar.

Iain

[nikp]

The vacuum hoses being the bundle of hoses underneath the intake plunum?

[rxangus]

Hmmm I have the same problem:

Around 0.8 bar before transition and 0.2 bar after. I also get a sound from the driver\'s side like high pressure air bleed off after transition but I suppose this may be the wastegate??

Going to take it to Pip at WGT to get it looked at.

Angus