Mazda Rotary Club

General => General Technical => Topic started by: AndyGen3 on July 25, 2012, 11:27:14 AM

Title: 3 issues if you can help ?
Post by: AndyGen3 on July 25, 2012, 11:27:14 AM
bought an FD with a suspected water seal failure.. didn\'t bother me as i was looking for a project over the winter and i got it for extremely good money..

have 3 issues with her..  

1st : water seal issue.. doesn\'t over heat and isn\'t losing water.. but on start up from cold the water pressure is mental !! is this normal ? their are a few bubbles when it calms down but not all the time ! the water pressure seems to be the big issue.. it has an.aftermarket astounded..

2nd : took the air pump off.. do you think i can find a belt to fit the car !! tried 7 different belts all 5pk fromt 733 to 768 and all are either just too small or way too big.. have an alloy pulley on her too which is a little bigger than stock..

3rd : first turbo  stopped working the other.day.. no boost until second turbo and no blow.off valve etc.. checked all pipes etc and theres no major noises from turbos.. exhaust note is seriously deeper too..

any help greatly appreciated..


Andy
Title: 3 issues if you can help ?
Post by: shaunwil on July 25, 2012, 02:44:07 PM
3rd Issue could be the rats nest (vacuum control pipes) or a sticking solenoid.

Can\'t help on 1st or 2nd, usually the champagne test is the best indicator of a bad water seal. Too long since I had an air-pump and I\'ve got rid of the water-pump too now for an electric one so belt is much shorter !

Shaun
Title: 3 issues if you can help ?
Post by: boosted on July 25, 2012, 05:55:45 PM
1.Water pressure mental when cold and ok when hot....summit warped so combustion pressuring coolant......champagne test cold? What does coolant look like? not full of kseal ....cooper/ bronze fillings? seen it in pistons and with cracked heads sort crack by sealing it by warm but when cold reopens.....

2. Motor factors by reg should have cross reference for belt.

3. go Non seq. Mine is and love it.

Just my curve ball on it......good luck
Title: 3 issues if you can help ?
Post by: andrewrx7 on July 26, 2012, 12:18:05 PM
Quote from: AndyGen3;8304233rd : first turbo  stopped working the other.day.. no boost until second turbo and no blow.off valve etc.. checked all pipes etc and theres no major noises from turbos.. exhaust note is seriously deeper too..


If i remember correctly, the 2nd turbo will only come "online" when the 1st is upto pressure. The flapper in the y-pipe is triggered at a certain pressure, derived from the 1st turbo. So you can\'t have a situation when the 1st turbo is not working, but the 2nd one is. They also work in parallel, not serial, so if one is not working you would most likely see a drop in pressure anyway.
Title: 3 issues if you can help ?
Post by: Bobbit on July 26, 2012, 03:28:39 PM
What I suspect is happening on the lack of 1st turbo issue is that same as mine. You will be getting a little pressure up to approx 4-4500 rpm then you\'ll get full boost. Turned out to be a faulty solenoid (3rd or 4th back if looking from the front of the engine) I can go into a full and rather dull explination of why this is happening but I\'m at work atm.

Search for a how to check a faulty solenoid guide I posted a few yrs back. Grab yourself a couple of replacement solenoids, loads of info on the rats nest, a spare day and go to town.  

You\'ll feel like a propper Rx owner once you\'ve fixed it too :driving
Title: 3 issues if you can help ?
Post by: Bobbit on July 26, 2012, 03:45:18 PM
Quote from: andrewrx7;830509If i remember correctly, the 2nd turbo will only come "online" when the 1st is upto pressure. The flapper in the y-pipe is triggered at a certain pressure, derived from the 1st turbo. So you can\'t have a situation when the 1st turbo is not working, but the 2nd one is. They also work in parallel, not serial, so if one is not working you would most likely see a drop in pressure anyway.

Not 100% accurate im afraid. You can have the 1st tubby making pressure but if a control flap is stuck open due to a faulty solenoid, all the pressure will be wasted and if feels like nothing is happening. Then at the change over you get full pressure and off you go like a rocket. This can be due to a faulty actuator on the y-pipe, of even the actuator for the turbo control, split pipe vacum pipe, solenoid etc. 99% of the time its the solenoids as they are nearly 20yrs old and the internal springs are knackered by now.

I suspect it\'s the y-pipe acutator control solenoid (try saying that after a skin full!) and just needs a new solenoid swapping over. It\'s a easy but time consuming job to change.
Title: 3 issues if you can help ?
Post by: AndyGen3 on July 26, 2012, 03:47:03 PM
Quote from: shaunwil;8304453rd Issue could be the rats nest (vacuum control pipes) or a sticking solenoid.

Can\'t help on 1st or 2nd, usually the champagne test is the best indicator of a bad water seal. Too long since I had an air-pump and I\'ve got rid of the water-pump too now for an electric one so belt is much shorter !

Shaun

Ineresting ! Might look into a electric pump.. Prob gonna get rid of power steering too so will only have altenator..

Quote from: boosted;8304571.Water pressure mental when cold and ok when hot....summit warped so combustion pressuring coolant......champagne test cold? What does coolant look like? not full of kseal ....cooper/ bronze fillings? seen it in pistons and with cracked heads sort crack by sealing it by warm but when cold reopens.....

2. Motor factors by reg should have cross reference for belt.

3. go Non seq. Mine is and love it.

Just my curve ball on it......good luck

Coolant is brown with with foam... Will try and get a vid.. Still never overheats(yet !) and not losing water.. But since ive put the oversized pulley on for the water pump the pressure seems to have increased even more !

Quote from: andrewrx7;830509If i remember correctly, the 2nd turbo will only come "online" when the 1st is upto pressure. The flapper in the y-pipe is triggered at a certain pressure, derived from the 1st turbo. So you can\'t have a situation when the 1st turbo is not working, but the 2nd one is. They also work in parallel, not serial, so if one is not working you would most likely see a drop in pressure anyway.

Bobbits reply below is exactly what is happening to mine.. So will have to re do the rats nest and go non seq..

Quote from: Bobbit;830519What I suspect is happening on the lack of 1st turbo issue is that same as mine. You will be getting a little pressure up to approx 4-4500 rpm then you\'ll get full boost. Turned out to be a faulty solenoid (3rd or 4th back if looking from the front of the engine) I can go into a full and rather dull explination of why this is happening but I\'m at work atm.

Search for a how to check a faulty solenoid guide I posted a few yrs back. Grab yourself a couple of replacement solenoids, loads of info on the rats nest, a spare day and go to town.  

You\'ll feel like a propper Rx owner once you\'ve fixed it too :driving

As said above this is exactly whats happening ! Will investigate further now I know what im looking for !

cheers lads for the replies :god
Title: 3 issues if you can help ?
Post by: AndyGen3 on July 29, 2012, 05:37:01 PM
Anyone know which solenoid controls the first turbo ??

found two broken vacuum lines but hasn\'t fixed the problem !
Title: 3 issues if you can help ?
Post by: shaunwil on July 29, 2012, 09:35:29 PM
Handy link off rx7club.com :

http://www.rx7club.com/3rd-generation-specific-1993-2002-16/vacuum-diagrams-stock-simplified-sequential-non-sequential-single-turbo-749702/#post8113663

Shaun
Title: 3 issues if you can help ?
Post by: Bobbit on July 30, 2012, 02:02:38 PM
Sorry not sure which solenoid does what off the top of my head.

BTW are you running standard boost?
Title: 3 issues if you can help ?
Post by: AndyGen3 on July 30, 2012, 03:49:32 PM
Theres a rattle too which wasnt there before ! :mad:

Boost is a little over .8

Mods are downpipe/full exhaust/twin filters and power fc...
Title: 3 issues if you can help ?
Post by: shaunwil on July 30, 2012, 06:49:07 PM
Boost should be around 10psi if running on stock pill (no controller) which is 0.7 bar

Shaun