that darned turbo!!

[hmltnangel]

Hi everyone, still having problems with the stupid second turbo on my baby.

:reallymad

The car seems fine now (thanks to Donato) The boost seems to be normal on the primary turbo (it\'s now sitting around 0.85 kg/cm instead of 1.1 kg/cm) but as I hit 4200 revs the boost seems to be dropping to around .6 kg/cm....... leaving me helluva short of power!

So the boost pattern goes like -----  0.9-0.6-0.6 gggrrr!

Any suggestions?  We did replace some of the vacuum hosing that had got really hard but not all of it - most of it seemed half decent. what should I check this time?  Someone said the one way valves on the hoses should be next but I don\'t fancy paying the clowns at Mazda 37 quid each to replace them! especially if they are ok.

[hmltnangel]

I don\'t know if this has anything to do with the same problem, I just remembered that when the car is at idle and I floor the throttle then let it go - as the revs drop down you get a click  must be around the point when the revs hit around 3k on the way down.

The only reason I bring it up is that it seems to be coming from the general area of the turbos. it\'s almost like something metal trying to open or close.

[Shark]

test the one way valves and judging by your symptoms I\';d recommend getting a vacuum tester from somewhere and checking the following.  

Charge relief valve
Charge control actuator
turbo control actuator

If you haven\'t already, also make sure that your problem isn;t in the vacuum chamber or the pressure tank.

This website has a brilliant testing process that I found helpful to rule out parts of the system.

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

Good luck!

[hmltnangel]

will this vacuum kit do the job of testing?

http://www.tooled-up.com/Product.asp?PID=18036&Referrer=Kelkoo

[Shark]

fraid not buddy - I couldn;t find one, but admittedly solved the problem bnefore looking very hard.

You need something that will create a vacuum and display it rather than just test one.

I mailed this company but got no reply.  
http://www.hubitools.com/home/default.asp?LNG=EN
They\'re UK distributors for mityvac, recommended on
http://www.autosportracetech.com/RX-7/TurboTroubleshooting.htm as per

at this point in your troubleshooting then a HIGHLY recommended tool to get is a hand-pump that can provide a vacuum as well as pressure, check out http:\\\\//www.mityvac.com. Just about any local auto-parts/tools place will have these, also don\'t forget to get some "T" pipe fittings and some vacuum hose to allow tapping into various hoses. Basically you can attach this to the various actuators and solenoids to see if the they operate properly, much nicer than having to run the car to test things out.

[hmltnangel]

mityvac 06810 automotive test kit?

The Automotive Test Kit offers a one-stop resource tor the testing of vacuum operated or vacuum related systems on a wide range of vehicles including automobiles, ATV\'s, boats and even airplanes. This kit tests all vacuum related systems in the engine including ignition systems, carburetors, automatic transmissions, computer systems, fuel systems, air conditioning units, cruise control units, emissions control systems and more. This kit contains the Mityvac® Repairable Vacuum Pump, Automotive Test Adapter Package, 1- 1/4" Rubber Cup Adapter, 24 inches of 1/4" I.D. Tubing and our 110+ page User\'s Manual.

what bout that one?

what was wrong with your turbo?

wheres best to get the one way valves? i\'m sure at least one of them is a goner!

[boltoa]

Soundsl like a classic example of the electrical connectors on the two solenoids near the pressure tank being the wrong way round. Swap them over and see what happens (you can\'t damage it doing this).

In the "Other Stuff" section here.

The click is normal - it\'s the air pump magnetic clutch engaging. Rev it with the bonnet open (manually with the throttle is easiest), and you can see the air pump stop at about 3500 on the way up, and start again about that point on the way down.

Good luck.

Andrew

[Shark]

Mine was the connector rod from the turbo control acuator.  it had popped off a mounting point so wasn\'t opening and closing the turbo control valve as it should.

That vacuum tester should do the job.  Basically, once you get into the second turbo area there is at least on point where the system requires both pressure and vacuum to work.  that seems to be where you need the tester.

The one way valves can be tested easily  -  If you disconnect the vacuum hoses from either end and try to blow through them - you should only be able to blow one way.  if you can\'t blow through either way then it needs replaced.  If you can blow through some easier than others then they may need replaced.

Follow the testing path on that website and it should help you to isolate the part of the system at fault.  At least then you\'re not testing everything.

I\'ve ordered a few odd bits from TW whites Mazda in Orpington - haven;t actually received anything yet but they\'ve been helpful in identifying little parts like springs etc for me and ordering them.  My local dealer tried to sell me an entire rear brake assembly and told me I couldn;t buy the spring on it\'s own     Otherwise Try Tim or Jimmy\'s for bits.

[Donato]

Glad i managed to help you a wee bit mate, hopefully you will get it sorted soon.

Cheers

Donato

[andrewrx7]

Originally posted by hmltnangel
I don\'t know if this has anything to do with the same problem, I just remembered that when the car is at idle and I floor the throttle then let it go - as the revs drop down you get a click  must be around the point when the revs hit around 3k on the way down.

The only reason I bring it up is that it seems to be coming from the general area of the turbos. it\'s almost like something metal trying to open or close.

Silly question, but you\'re not mistaking the airpump clutch engaging/disengaging for something else? This has an audible clicking sound as it cuts in and out, and I thought it did so around the 3k mark?

[andrewrx7]

Originally posted by Shark
Mine was the connector rod from the turbo control acuator.  it had popped off a mounting point so wasn\'t opening and closing the turbo control valve as it should.

I also had a similar problem a few years back. The inlet gasket was replaced, and the actuator rod to the 2 turbo gate was done up too tightly. Went out for a spin, fine trundling along at 40, came to a dual carridge way - booted it......good acceleration.....then slowed for a roundabout, then little power after that......
On closer inspection, the end of the actuator rod should have (I think) a split pin to stop it from coming away. On mine, when it had a rebiuld, the builders must have put on a nut and bolt, and this was tightened too tightly. Hence the first hard drive was OK....the 2nd turbo was allowed to come online in the right way, but then the actuator stayed open \'cos it couldn\'t return, which meant that the gasses were bypassing the 1st turbo (so not spooling), and hence no power. I simply loosened the nut/bolt a touch, and everything was fine after that. Not saying this is your problem (unlikely), but it can sometime be the simple things that cause the biggest of headaches!

Good luck!

[bobster]

The actuator rods are held on with the worst CirClips in the world....


What has been done to the car in terms of tuning? .... If it is stock I would say that this is pretty much what will happen.

I would tend to agree that the problem could be the 2 solenoids behind the pressure tank being the wrong way round..... there is a connector and a solenoid with a white dot on them ... addly these go together.
I would say that is more likely to be this or an issue with the control system just because the problem happens round about transition when the boost controlling function


There is also the outside possibility of it being a dead CAT.... if you still have it... Not totally certain of the symptoms but will cause boost problems higher up the rev range.

[Donato]

It looked pretty much standard apart from a cat removal. ECU looked standard as well. It had a partial vac hose replacement, the ones i changed were well and truelly cooked, as flexible as the tax man in fact...

[hmltnangel]

upon more looking I found this little "thing"  lying split apart

what is it?

thats the throttle cable at the top.

this is the view when you take the pressure chamber off.

from the front of the car - it\'s a little black thing that had a spring inside - smaller than the one way valves, it was split apart. (oh, the spring has decided to do a journey to thecentre of the engine. dunno how to retrieve it)

[Shark]

can\'t make out much in that picture - but
if it\'s broken
and the rest of the car is fine
it;s probably your problem.

replace and away you go with some proper booooooosssttt!!!