Help needed - no boost in secondary turbo in FD

[partyman76]

Hey guys

Seems as though the secondary turbo in my FD isn't boosting. It seems that my primary boosts early then falls away, and that's it. Secondary turbs does nothing! I'm guessing some hose is come off or something simple (I'm hoping anyway).

Anybody have any experience in the area? I don't have time to get it to a rotary workshop either as I live in the southern suburbs and can't get to any workshops easily.

Edit: I should also add that I changed the mid pipe and rear section of my exhaust today to something more free flowing.

Cheers
Dan

[miket]

check the rx7club.com forum then search fd turbo problems there is a heap of info ( just need to search through the posts )

good luck ...

[binnzy]

Hey bud, check all your vacuum lines..... Simon (capella re) had this same problem... you may have knocked one off fitting your pipes??

[partyman76]

Thanks guys. Had a look through rx7club and there are so many different things that can do this! I'm going to book it in for a service and get a workshop to diagnose it. It may even be the exhaust I put on - it was second hand and may be a rooted cat. Farken rotaries!

[capella re]

That's correct, I had the same issue. Did the change happen after you fitted the exhaust? I couldn't really see that being an issue unless the boost spiked and blew a vacuum line off in the rats nest under the inlet manifold. Big problem with the fd's as you would be aware from googling it.
Could be a million things but I got lucky and it was simply 3 vacuum lines had come off at some stage so just reattached and zip tied the suckers to stay there. Just be careful of someone incompetant looking for the issue, there's a lot that COULD have gone wrong to cause this and labour can build up very quickly to diagnose what the problem is. Best sticking with someone that has experience in that, to save labour checking things like wastegate arms which are less likely to be the cause.
I had good experiences with sean at boostworx even though he is a bit far for you, could save you headaches in the long run though as he is well versed in the twin turbo set up.
Don't stress too much, can be something really simple, if your mechanically inclined, pull the inlet manifold up and have a squiz for any of the vacuum lines that may have come off. I'd do that before even considering one of the turbos actually having a problem. Other than that, theres a bunch of solenoids which can give up and require testing as well.
Good luck, it'll just be something simple, only headache is finding it.

What does the boost gauge look like when it happens? Mine went 10psi, then to the transition of the secondary kicking in it would drop to the normal 5psi at about 4000 4500 then nothing instead of going back up to 10psi for the secondary.

[miket]

Hey bud, check all your vacuum lines..... Simon (capella re) had this same problem... you may have knocked one off fitting your pipes??

I think he went to boostworx and they fixed it, tuned it and it made good power....:rapide:

Michael..

[partyman76]

Thanks for the info Simon. I can't be 100% sure, but I think it happened when the different exhaust went on.

I would love to go to boostworx, I've used Sean many times for other cars I've had. But the distance is too far - I have a work car that I have to take to work every day (at Noarlunga!).

I rang Greg at Mildrens at 7.30am this morning and had a chat to him. He has already said that it is most likely a vacuum hose or maybe a solenoid. He gets them quite frequently apparently. I've booked it in for Monday week to get a service and for them to sort it out.

In the mean time I might try and have a look under the inlet manifold as you suggested.

Cheers
Dan

[Hyperdrive3d]

If you take your strut brace off, remove the black container(boost resivoir) you will then be able to see the turbo control solenoid. Its an easy fix to do yourself(if thats the problem) rather than paying heaps for a 5min job.

[partyman76]

Got a pic of what this boost reservoir looks like Jason?

[capella re]

http://www.fd3s.net/vacuum_hose_diagram.jpg

the vacuum setup, very complex, don't try and understand it

http://www.fd3s.net/vacuum_hose_2.jpg

as it sits in real life, all located under the inlet manifold.

Your not expected to know, nor learn any of this. Just look for inconsistencies, hoses or nipples not attatched. Degraded hoses, brittle etc. Just look for obvious stuff, try not to pull it apart, disaster to work out if you attatch hoses back together wrong. Also due to the heat under the bonnet, nipples and solenoids can get brittle and break (just plastic)

Try not to research the fd too much, people tend to complain a lot about them and it'll depress the shit out of you reading it all. It's a small problem and you'll be buzzin again in no time.

[partyman76]

Jesus Christ. I suppose it will be a huge effort just to remove the intake manifold before I even see that spaghetti!

[Hyperdrive3d]

http://www.fd3s.net/vacuum_hose_diagram.jpg

Boost resivoir is the pink box thing about half way up on the right side in the picture above(pressure chamber)

http://www.fd3s.net/vacuum_hose_2.jpg

When you take the pressure chamber off(and strut bar) you can see most of this, without removing the intake manifold. Notice the 2 pale green solonoids just to the right of the front rotor intake tube, the one that has the white dot on the plug is the one that controls the boost.

I have heard that the solonoid with the dot on it has a habbit of breaking so i would try that first...

[redrx]

I had the same thing with my FD and it was a single check valve failure. One you can change without having to touch the rats nest or remove anything (and for me that was the one the one that failed, happy days!), the others require a bit more work.

Its worth trying this before spending time and $'s on all the other stuff! You wont regret having the check valves regardless, from what i've read the factory ones are prone to failure. A set of replacements is about $30 from ebay. The Viton ones are the ones u want, reputedly a big improvement on the stock ones.

More info and picks of where to find them here:
http://www.fdrx7.com/forum/showthread.php?t=205

For more info about the sequential twins:
http://www.fdrx7.com/forum/showthread.php?t=8183

[partyman76]

Thanks guys, that's a great help!