damn-dgeesaman- you changed your picture and now you messing me up when i scroll down threads

What are your thoughts on spraying silicone spray into a sticky rack solenoid?

You could try it, but nothing I've tried has worked to unstick a sticky solenoid.

so you guys spoke of using a power supply and this is my take on it
did this this afternoon
it also works for testing car electronics, as you can see im testing a dvd deck i pulled out of a 240 i bought
let me know what you think, i think it should be easier to test solenoids with this rather then holding 3 wires at once and pumping the mityvac while trying to watch for leaks.


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Are the small and large diameter check valves interchangeable or do I need to make retain size consistency when changing these check valves?

A check valve is a check valve.

Do a search for "Dale Clark". He will sell you some nice check valves which use a VITON (damn near indestructible) diaphragm. They are smaller, nicer and way cheaper than OEM. Don't quote me...but I believe he will ship you four for $15 give or take a couple bucks. Get a half dozen then you'll have a spare of two depending on how many you want to swap out.

They also have a single 'barb' on each end and stay very well.
-----> http://cgi.ebay.com/ebaymotors/_Car-...1%7C240%3A1318

You are FANTASTIC, the information you give is price less to all of us RX7 owners who mechanic on our own cars, because most Mazda Dealers are FRIGHTENED of the word RX..
Keep up the great work as this sight will be looked at by future historians of the RX7.

Fantastic writeup

Thanks! This is exactly what I was looking for. Your help is appreciated.

dgeesaman:
GREAT POST . Posting my problem and test results to help others.

Backround:
purchased a stock twin sequential with light mods (silicone rat's nest hoses, pfs smic, 99 twins, pfs dp, pfs intake)

Problem:
Boosted 10-8-10 at purchase (July), but developed a 14 psi spike at 4500 rpm (Sept), and base boost increased to 12 psi

Tests:
Checked all turbo control actuators, they were ok.
All silicone vacuum lines were ok.
Decided to run the solenoid tests after finding this post.

Results:
All solenoids activated properly at 12 volts and ambient temp
All solenoids passed leak tests at ambient temp
2 solenoids failed to activate at 9v and ambient, charge control and relief (acv)
All 7 rack solenoids (items a-f in diagram) failed to open at 9v and 250 degree F (hot)
However, 6 of these solenoids opened at 12v and 250 degree F

https://www.rx7club.com/showthread.p...charge+control

Conclusion:
I ordered 3 new turbo control rack solenoids, and replaced others with used solenoids that tested ok.
Thanks again for this post it was a huge help

Since all failed rack solenoids were the 7 in-line nearest the engine block, I'm guessing radiant engine block heat caused the failure. Rather than relocate the solenoids, I added Thermotec insulating fabric as shown in pics.

How effective is/will the insulating fabric be against heat soak?

Is this really not archived? Needs to be if not.

It should be in the FAQ. The archive hasn't been in use as much.

Dave

degeesaman agree with faq, seems that most don't realize that the solenoids are a huge problem (I didn't).

beckrx, good question. I'm sure a vented hood helps a lot, of course.
For those of us that have a stock hood, not sure. One idea (not completed), perhaps a time delay relay that turns the engine cooling fans on for a few minutes, after shutdown. Kinda like a turbo timer, it would force air through the engine compartment, and lower heat soak temps, that would help the underhood component durability

I just updated the FAQ with this link.

Just received 3 new solenoids from Malloy:
Pressure regulator (13-240A)
Charge Control (13-240A)
Turbo Control ((18-741)

Test Results @ ambient:
2 of 3 failed to open with 9v,
but all 3 would open @12v
(they are a little "tight" when new??)

Test Results @250 deg F:
3 of 3 failed @ 9v,
again all 3 opened properly with 12v

Comment:
agree with M104-AMG: even new valves fail @9v, however all should pass @12v.

Conclusion:
Test at ambient and hot, but use 12v ............

That is sad. I was about to order some new stock solenoids to try and fix a problem with my transition (or lack of a transition to the secondary turbo). No secondary boost. :(

I'm going to do some research and see if I can replace one of my bad solenoids with one of these:
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/custom-replacement-solenoid-system-404243/page8/

As I said earlier in the thread, the solenoids do not operate at 9v. They operate at 12v but I usually use a fresh 9v battery because I'm lazy about finding a 12v source. If you get different results at 12v then disregard what you did at 9v.

The Mazda parts probably sat on a shelf for years. If it take a couple of cycles to get them moving it would not concern me much.

Dave

I cycled NEW solenoids about 25-times, and they still failed . . .

:-( neil

I always prop the hood open after I turn off the car, wait five minutes then turn the key to the "run" position which turns on the fans. I then let the fans run for about fifteen minutes. I am unconcerned with battery drain since I use a battery tender.

As to solenoid testing, I use an AC/DC adapter with an adjustable output setting (a universal adapter). I cut off the connector, stripped the two wire ends, connect the leads to the part and switch between 9v and 12v when testing.

I recently installed all new solenoids that I purchased from Ray at Malloy Mazda. (Thank you dgeesaman for taking the time to respond to all my PMs on solenoid testing.) My neighbor M104-AMG told me that I would probably have a 50%+ failure rate testing new solenoids and he was right. I was afraid that I was irritating Ray when I called him to order replacement solenoids. However, he swapped out the failed solenoids without hesitation. I am glad I tested each one. Since rebuilding my rat's nest, my car has never run better.

I also learned from Ray that although the solenoids all look alike, there are specific part numbers for specific solenoids. The following are the number of solenoids needed, the part number and the purpose.
(3) 1480-13-240A. Double throttle control, charge control and charge relief.
(1) 1481-13-240A. Pressure regulator control.
(2) 1482-13-240A. Secondary air bypass, EGR.
(1) N390-18-741. Turbo control.
(1) N3A7-18-741. Secondary air switching valve.

Finally, the painted numbering/lettering sequence on the solenoid identifies what they are for. Ray said that there are two rows of painted numbers on each solenoid: the upper and the lower rows. The lower row identifies the solenoids as follows:
"1" corresponds to part number 1482-13-240A. Secondary air bypass, EGR.
"2" corresponds to part number 1481-13-240A. Pressure regulator control.
"3" corresponds to part number 1480-13-240A. Double throttle control, charge control and charge relief.
"82" corresponds to part number N390-18-741. Turbo control.
"17 corresponds to N3A7-18-741. Secondary air switching valve.

Eww. Sounds like shelf life is getting to be a serious problem.

I bought some new ones a few years ago (ok, maybe 6 years by now) and didn't have any duds. It doesn't seem that way anymore.

They are certainly marked per location and the filter basket will be in the right location for you. But if you ignore the markings and move the filter baskets around I have yet to find any difference in build and performance.

Dave

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/why-engine-so-damn-complicated-part-3-cooling-fan-controls-876767/

beckrx see above still thinking about heat soak........

I Have Put these instructions together in a PDF. If someone wants to host it or have it emailed I can do that.