Great thread! Everything I needed to figure out my secondary turbo issues was here. I ended up ordering 9 new solenoids from Mazda (all except the purge solenoid and the WGA/PCA solenoids that I already replaced with MAC). At room temp, some of the brand new units tested out fine with 9v, but some were sluggish switching while under vacuum and some wouldn't switch at all. They all tested fine with 12v. YMMV.

 

Any info on testing turbo wastegate actuators?

 

Plug one nipple, apply pressure to the other, and if it opens at the specified pressure and does not leak, it passes.

 

That's not surprising - more voltage = stronger magnetic pull.

The "release" test however is based on internal friction and the strength of the plunger spring and should not be driven by voltage / field strength.

David

 

I have been chasing a boost problem, thread here: https://www.rx7club.com/3rd-generati...usion-1090414/

I just pulled and re-tested all my existing solenoids and they appear to be good.

I ordered a brand new set of solenoids from Ray, not knowing there were potentially different solenoids. I just told him the solenoid names via e-mail, and so I received:
(2) 1480-13-240A. charge control and charge relief.
(1) N390-18-741. Turbo control.
(1) N3A1-18-741. Turbo control (Vacuum)

Upon comparing to my old solenoids that tested good, I was using a 1480-13-240A solenoid for turbo control where I should have had N390-18-741. All of my old working solenoids were the same, (1480-13-240A). If my boost issue fixed we shall see if that 3-way turbo control really is different or not. Either that or I had a bad solenoid that was testing good.

 

did you test your good solenoids hot? I had a bunch fail hot that passed cold. Remember, they are supposed to work in a hot environment.

Also test the new ones as well. I read somewhere (maybe in this thread) that the new ones are not necessarily new and have been sitting some time and occasionally test bad.

 

Yes, I tested them all both cold & hot.

 

Car boost perfectly now! Either the solenoids are picky or something was testing correctly but didn't work when it counted.

 

should the turbo control actuator hold pressure and vac as shown in this diagram?
i can't get my first turbo to boost past 4.5 / 5 psi chased everything else and the vac system is fine wastegate and pre control all working and connected as should

thanks in advance


m?

 

Yes, the actuator should. The pressure and vacuum are applied simultaneously in operation to make the actuator operate quickly and shut the TCV securely.

 

Thanks, checked all my vac lines and had this off the car and its not holding pressure on the side fitting so just waiting on a replacement

 

First off, let me apologize for the 9 year comeback for this thread, but it's got lots of good info and seemed like the best place for this. I'm currently going thru an FD and started testing the solenoids. I had 1 solenoid that was DOA; there was no continuity on the coil so I thought it would be fun to see what's inside so people can see how they work and what the failure points really are. So this is the insides of the solenoid:


The bullet looking guy with the black tip is the only moving part. The black tip is actually a rubber seal that seals up against another cone inside the solenoid.


When the coil is not energized that little spring pushes the tip of the plunger into the housing sealing the "A" to "B" path and leaving the "B" to "C" path open. Then the coil energizes it pulls the plunger back into the right most port housing. There's an oring seal on the backside of the plunger that seals against the housing opening the "A" to "B" path and closing the "B" to "C" path. This solenoid likely would have leaked out port "C" due to the corrosion on the right port housing.


Interestingly enough all that debris on the plunger seal was inside the solenoid already which made me think that some of the failed solenoids might just need a good cleaning if the plunger is still moving fine. I had a few solenoids that leaked a tiny bit so I thought i'd try giving them the old razzle dazzle and see if they came back. I popped the whole solenoid into an ultrisonic cleaner with a little simple green and warm water in it. During the cleaning I did actuate the solenoid for a bit, and after the bath I immediate flushed them with WD40 to remove any remaining water and cycled the solenoid several times. To my enjoyment, every single solenoid that I cleaned is holding pressure and vac now. Your results may vary, but it worked really well for me and is certainly worth a try if you have access to an ultrasonic cleaner.

 

That’s very good info! I recently bought a few of these from Mazda, and they were all DOA, I’m gonna have to try this out.

 

Nice to see this. Its kind of what I had been thinking. Not much to go wrong with these aside from the plastic being super brittle with heat and age. I don't see coils really going bad because they aren't high current. Debris in the system is a definite possibility. If you can pull them off without them breaking them, cleaning would be an option but that would be the hardest part IMO. I've done the same with new solenoids. They may "fail" a test on delivery but they could just need cleared out. Manufacturing debris could be inside and after a few cycles under pressure or vacuum they may self clean.

 

Well done.

I recall that some failed solenoids would just leak, some didn't cycle, some cycled slowly, etc. The ultrasonic makes excellent sense. I always assumed there were elastomer seals inside that were degrading but those overall looked pretty good. So that means maybe it's mostly dirt causing issues.

 

i just found this, which might be an interesting choice for someone with an aftermarket ECU.
GM 12649146, turbo solenoid for a Chevy Malibu.
it looks a lot like the Mazda part, but with an EVI connector

 

wow this forum is still alive after all these years. so cool to see. I joined over a decade ago but haven't been back for a while

 

I'm in the process of solenoid testing now and some of rack solenoids doesn't release pressure fast enough when energized but they hold vacuum so I can use them where there is only vacuum. And some doesn't hold vacuum good enough when energized but hold and release pressure fast as per first post. So could you pls point me where I can use "vacuum good" solenoids and where "pressure good" solenoids?
Thanks

 

Pressure lines only in one of these diagrams.

https://www.fd3s.net/vacuum_hose_replacement.html

 

Thanks! Exactly what I need