Mazda Rotary Club

General => General Technical => Topic started by: hmltnangel on October 25, 2004, 08:49:50 PM

Title: that darned turbo!!
Post by: hmltnangel on October 25, 2004, 08:49:50 PM
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.
Title: that darned turbo!!
Post by: hmltnangel on October 25, 2004, 09:16:44 PM
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.
Title: that darned turbo!!
Post by: Shark on October 25, 2004, 09:24:48 PM
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!
Title: that darned turbo!!
Post by: hmltnangel on October 25, 2004, 09:51:22 PM
will this vacuum kit do the job of testing?

http://www.tooled-up.com/Product.asp?PID=18036&Referrer=Kelkoo
Title: that darned turbo!!
Post by: Shark on October 25, 2004, 09:57:02 PM
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
Quoteat 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.
Title: that darned turbo!!
Post by: hmltnangel on October 25, 2004, 10:10:49 PM
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!
Title: that darned turbo!!
Post by: boltoa on October 26, 2004, 09:46:56 AM
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 (http://www.autosportracetech.com/RX-7/TurboTroubleshooting.htm).

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
Title: that darned turbo!!
Post by: Shark on October 26, 2004, 11:04:47 AM
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  :eek:   Otherwise Try Tim or Jimmy\'s for bits.
Title: that darned turbo!!
Post by: Donato on October 26, 2004, 11:35:23 AM
Glad i managed to help you a wee bit mate, hopefully you will get it sorted soon.

Cheers

Donato
Title: that darned turbo!!
Post by: andrewrx7 on October 26, 2004, 12:42:40 PM
QuoteOriginally 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?
Title: that darned turbo!!
Post by: andrewrx7 on October 26, 2004, 12:50:51 PM
QuoteOriginally 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!
Title: that darned turbo!!
Post by: bobster on October 26, 2004, 07:43:04 PM
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.
Title: that darned turbo!!
Post by: Donato on October 27, 2004, 08:45:25 AM
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...
Title: that darned turbo!!
Post by: hmltnangel on October 27, 2004, 09:53:29 PM
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)
Title: that darned turbo!!
Post by: Shark on October 28, 2004, 02:13:32 PM
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!!! :D
Title: that darned turbo!!
Post by: hmltnangel on October 28, 2004, 11:44:24 PM
right, I\'ve concluded that this little black thingy is the cause of all the problems! I put it back together again then took my baby out for a drtive and...........



yyyyyyyeeeeeeeehhhhhhhhaaaaaaaarrrrrrrrrr!!!!!!!!!!!


the second turbo came online at the right time so my boost looked a bit like


0.85, 0.5, 0.8 kg/cm!

This sound normal to anyone?

I then went  to try hard boost again and it had went back to the way it was before.

i was puzzled until i got jome and the little black thingy was split again!
Title: that darned turbo!!
Post by: bobster on October 29, 2004, 07:31:27 PM
There are a few little black thingies about.....

There are a couple of hoses that just vent to the atmosphere, these normally just have little filters on them.... I could probably tell you what it is if I saw it.



Also.... Yes that should be the correct boost pattern.
Title: that darned turbo!!
Post by: hmltnangel on October 29, 2004, 08:06:26 PM
don\'t have a good pic till the morning but it looks like the one way valve thingies except it\'s smaller and all black
Title: that darned turbo!!
Post by: hmltnangel on October 29, 2004, 08:11:00 PM
IF YOU CAN MAKE THIS OUT......
Title: that darned turbo!!
Post by: hmltnangel on October 29, 2004, 08:12:34 PM
in that pic the pressure chamber has been removed,

the thing is all black and about 1/2 inch long and it sits inline on that hose that dissapears down into the engine.
Title: that darned turbo!!
Post by: hmltnangel on October 30, 2004, 02:04:04 PM
this is the offending pice of equipment - any ideas folk on what it is?
Title: that darned turbo!!
Post by: Shark on October 30, 2004, 11:39:21 PM
looks like a replacement for a one-way pill valve.

The hoses connected to it, where did they go?
Title: that darned turbo!!
Post by: hmltnangel on October 31, 2004, 04:09:17 AM
standing at the front of the car ......

one end goes onto a connection behind the pressure chamber - under the intake on the very right hand side. The furthest hose on the right under the intake...... points towards the front of the car.

I\'ll get a pic up in the morning.


Symptoms now sound like it is the pcv valve - its obviously now stuck open as the spring inside it vanished and i seem to be a little short of boost on the second turbo, on the plus side i can now feel the second turbo coming online.

Now my bloomin exhaust has started rattling a little bit!

Gonna do a coolant and oil change next weekend - I just got the car so I dunno when it was last done. The coolant looks old though and the oil is a little dark.

What oil would you reckon, coolant too for that matter? Also where will i get a lovely oil filter to keep the oil clean? and lastly - i\'m assuming that there is a guide for coolant change and oil change on the forum?
Title: that darned turbo!!
Post by: bobster on October 31, 2004, 10:57:00 AM
Oil - castrol 10w 40 or 15w 40..... make sure it\'s mineral.

The rotary engine injects a little oil into the housing and some synthetics may contain plastics that can leave deposits as they burn. So mineral oil only unless you can get your hands on some of the special rotary synthetics.

Any form of coolant is fine..... you might be able to get some water wetter to add to the coolant which increases the efficiency of the coolant. Not necessary but good if you can get it.
The coolant system is a total bitch to burp.... it will take along time to do.....just keep topping it up and running the engine and topping it up and running the engine and topping it up and running the engine and topping it up and running the engine. get the picture.


While you are under the car doing the oil pull the plugs out and make sure they aren\'t too fouled up.
Title: that darned turbo!!
Post by: Shark on October 31, 2004, 01:43:12 PM
QuoteOriginally posted by hmltnangel
Gonna do a coolant and oil change next weekend - I just got the car so I dunno when it was last done. The coolant looks old though and the oil is a little dark.

What oil would you reckon, coolant too for that matter? Also where will i get a lovely oil filter to keep the oil clean? and lastly - i\'m assuming that there is a guide for coolant change and oil change on the forum?

There is a sticky in the forum on how to change oil and coolant by Wav I think. - I worked from this for my coolant change yesterday, though I didn\'t drain the block, just the rad.  One word of advice if you have an undertray - the how to says to remove it, but there is a circular hole exactly below where the rad drain hole is.  I thought I\'d be smart and ended up with coolant all over the place until I got the drain hole plugged again. - TAKE THE UNDERTRAY OFF FIRST, is the moral of the story.
For the coolant, a 50/50 mix of aluminium friendly antifreeze and de-ionised water should do the trick.  I added 2oz of water wetter to every two litres of coolant.  Draining rad only took and 5 litres \'ish.  Takes bloody ages to do this as has already been said.

Oil is easy, you\'ll get a filter from halfords, or go to mazda and get a filter and new sump nut washer if you don\'t know when it was last done - check the sump nut before you go to start - I had to use a hammer to get a socket onto mine cos the head was so ripped by whoever last changed the oil.  You\'ll need about 4.5 litres of oil.