20K mile switch?
08-13-04, 12:15 AM
#3
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Not really, but your close...
The port air solenoid and the split air solenoid are two different animals on the ACV. There's a good cutaway drawing of it in both the Haynes and the FSM. During the first 20K of the car's life, the little port air solenoid (the front one on the S4 ACV) injects air from the air pump directly into the exhaust port areas of the rotor housings, through passages built in to them (the EGR systems also uses built-in passages). After 20K, this solenoid is supposed to be no longer operational (0 volts at all times to the solenoid). I've heard rumors that every 100,000 miles, the switch kicks "in" again for another 20K miles, but I have not been able to verify this.
The split air solenoid controls the cat air. When it is not energized, some air is routed to the port air passages by design, just like the port air solenoid did. When energized, the air is routed to the cat. This operation also depends on the switching valve position (and the relief valve, which will exhaust all ACV air overboard through the "silencer" during certain engine/rpm events).
The port air solenoid and the split air solenoid are two different animals on the ACV. There's a good cutaway drawing of it in both the Haynes and the FSM. During the first 20K of the car's life, the little port air solenoid (the front one on the S4 ACV) injects air from the air pump directly into the exhaust port areas of the rotor housings, through passages built in to them (the EGR systems also uses built-in passages). After 20K, this solenoid is supposed to be no longer operational (0 volts at all times to the solenoid). I've heard rumors that every 100,000 miles, the switch kicks "in" again for another 20K miles, but I have not been able to verify this.
The split air solenoid controls the cat air. When it is not energized, some air is routed to the port air passages by design, just like the port air solenoid did. When energized, the air is routed to the cat. This operation also depends on the switching valve position (and the relief valve, which will exhaust all ACV air overboard through the "silencer" during certain engine/rpm events).
08-13-04, 12:32 AM
#4
You seem to have a pretty firm grasp on the operation, I was thinking since they were part of the same unit, the air passes through to the ACV... at least that's what I took from the S5 N/A diagram of the unit.
Perhaps you could shed some light on this situation here:
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/possible-causes-pasv-ecu-code-33-a-331672/
Thanks
-Mike
Perhaps you could shed some light on this situation here:
https://www.rx7club.com/2nd-generation-specific-1986-1992-17/possible-causes-pasv-ecu-code-33-a-331672/
Thanks
-Mike
08-13-04, 09:05 AM
#5
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On a series four car............It's not a rumor. Everytime you come up to a 100,000 mile interval the Port Air Solenoid WILL once again be energized....until you hit 120,000 miles whereupon it turns into a pumkin once more. Been there, seen that.
But back to the original question: Read what Wayne said. It's not something you'll ever notice driving the car.
But back to the original question: Read what Wayne said. It's not something you'll ever notice driving the car.
08-13-04, 10:20 AM
#6
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I'll be able to verify this soon, Hailers, as I'm at 191,000 (and the port air output at the ECU is 0v as it should), and will hit 200K by the end of the year (I'll check it again then just for my own amusement). It won't really matter on my car anyway, as the port & split air solenoids are no longer electrically "active", I've got her rigged to continuously dump cat air to tame the pollution, lol...
Not that I don't trust you, lol...
Not that I don't trust you, lol...
08-13-04, 10:25 AM
#7
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F1 Blue, first of all, what is code 33? Port air system? Second of all, when Mazda says "2.5 volts or below", they really mean 0v, or, no voltage, or, de-energized. So, you're going to have to explain the exact problem you're having for me to help you much (disclaimer- if the S5 ACV systems is much different from the S4's, I won't be able to help much anyway)
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08-13-04, 11:06 AM
#8
Originally Posted by WAYNE88N/A
F1 Blue, first of all, what is code 33? Port air system? Second of all, when Mazda says "2.5 volts or below", they really mean 0v, or, no voltage, or, de-energized. So, you're going to have to explain the exact problem you're having for me to help you much (disclaimer- if the S5 ACV systems is much different from the S4's, I won't be able to help much anyway)
Who knows. It's not causing problems.
08-13-04, 11:24 AM
#9
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As many problems as I've read about that sucker shorting out (and sometimes taking the ECU with it), you might have a shorted port air solenoid (although it shouldn't be energized at this point). Try disconnecting the electrical connector from it in the engine bay to see if that helps (although an "open circuit" might be what's triggering the code). And, if that's the case, the solenoid coil itself might have burned out. Read the solenoid out with a meter set to resistance, you should get just a hair above 0 ohms (it is, after all, a coiled wire). If you get nothing, then it's open- which might be why the code is popping up. If you need it for emissions, I'm sure there are lots of guys with "spare parts" that'll "sell" you theirs, since it seems no one has their ACV on the car anymore...
08-13-04, 01:29 PM
#12
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You can read out the 20K switch at the input to the ECU (pin 1C on S4's, large plug, 2nd upper pin from the right), should be no voltage. If there's 12v there, then the switch thinks the car is back to the 0-20K mark again...
Or, you can check the port air solenoid voltage to ground, either at the ECU (pin 1S, same plug, 3rd upper one over from the left), which will read approx. 0 volts with the switch on (the solenoid is energized, "dropping" the 12v, which is why you'll read 0 there). Or, at the port air solenoid connector, in the engine bay (with it disconnected, if you get 12v to ground (or the other pin in the plug) on the harness side, then the switch is "on"; let us know how it turns out...
Or, you can check the port air solenoid voltage to ground, either at the ECU (pin 1S, same plug, 3rd upper one over from the left), which will read approx. 0 volts with the switch on (the solenoid is energized, "dropping" the 12v, which is why you'll read 0 there). Or, at the port air solenoid connector, in the engine bay (with it disconnected, if you get 12v to ground (or the other pin in the plug) on the harness side, then the switch is "on"; let us know how it turns out...
08-13-04, 04:55 PM
#13
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is that all the 20k milage switch does, i thought it also made less hp under 20k until it switches to a different map. also does the switch activating at 100k affect s5's? i had a feeling that my car wasnt making the power it should have between 100k and 120k, but after that it ran quite a bit better.
08-13-04, 07:42 PM
#14
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So it should be on even when the car is not running, correct? I still want to see a pic of where I should check, I dont want to screw something up accidentally. and I wan't be able to check it until next wenesday, I'm leaving soon for a trip to missouri and I'll be gone until late tuesday.
08-13-04, 09:15 PM
#16
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Get a 17mm size wrench. Remove it , the Port Air Solenoid Valve from the acv. It's the most fwd of the two. Use care. There is a very small spring and poppet there inside it. Take the spring and put in a safe place. Offer the poppet valve up to the inside of the Port Air Valve. See how if you invert the Port Air Valve how gravity will let the poppet fall to the ground? Now turn the key to the car ON. Place the transmission in fifth gear. Go back and reinstall the poppet valve into the Port Air Solenoid. Invert it. Now gravity is defied and the poppet remains in the valve. NOTE: the above is done with the elec connector of the Port Air VAlve installed on the car harness...duh.
The above only works on a car b/t 0 and 20,000 miles or 100,000 to 120,000 miles or......you get the drift.
Oh, remove the poppet during emissions inspection. A little more Port Air never hurt during testing. It ain't a lot of air, but a little bit more. Tell your girl you need a little more. See? A little more never hurt.
The above only works on a car b/t 0 and 20,000 miles or 100,000 to 120,000 miles or......you get the drift.
Oh, remove the poppet during emissions inspection. A little more Port Air never hurt during testing. It ain't a lot of air, but a little bit more. Tell your girl you need a little more. See? A little more never hurt.
08-13-04, 09:38 PM
#17
Originally Posted by HAILERS
Get a 17mm size wrench. Remove it , the Port Air Solenoid Valve from the acv. It's the most fwd of the two. Use care. There is a very small spring and poppet there inside it. Take the spring and put in a safe place. Offer the poppet valve up to the inside of the Port Air Valve. See how if you invert the Port Air Valve how gravity will let the poppet fall to the ground? Now turn the key to the car ON. Place the transmission in fifth gear. Go back and reinstall the poppet valve into the Port Air Solenoid. Invert it. Now gravity is defied and the poppet remains in the valve. NOTE: the above is done with the elec connector of the Port Air VAlve installed on the car harness...duh.
The above only works on a car b/t 0 and 20,000 miles or 100,000 to 120,000 miles or......you get the drift.
Oh, remove the poppet during emissions inspection. A little more Port Air never hurt during testing. It ain't a lot of air, but a little bit more. Tell your girl you need a little more. See? A little more never hurt.
The above only works on a car b/t 0 and 20,000 miles or 100,000 to 120,000 miles or......you get the drift.
Oh, remove the poppet during emissions inspection. A little more Port Air never hurt during testing. It ain't a lot of air, but a little bit more. Tell your girl you need a little more. See? A little more never hurt.
ahahahaha....
Sometimes it hurts if you keep asking for a little more.
08-14-04, 12:42 AM
#18
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Hailers, there you go with that 5th gear thingy again, lol...So now you're saying the split air AND the port air are both energized in 5th (with the 20K switch on, anyway)? Remember, the 5th switch is open (no continuity) in 5th gear, so it can't be grounding anything. The ECU must be doing it through its own grounds once it loses the 5th switch's "ground signal", so to speak. I'm not doubting you here, understand, because it sounds like you have "played" with these solenoids on the car to see for yourself what's going on. I just figured once the 20K switch is "on", the port air solenoid would be energized ALL the time, not just in 5th.
I like your strategy, though, that way he doesn't have to tear anything apart to get to the ECU...
I like your strategy, though, that way he doesn't have to tear anything apart to get to the ECU...
08-17-04, 11:32 PM
#19
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Ok. I had my head stuck up my dark spot when I wrote that. I wrote as if I were checking out a Split Air Solenoid instead of a Port Air. Yeah, Port Air is energized from zero to twenty grand and then not engergized again til one hundred grand. What I wrote will work for a Split Air Solenoid though.
08-17-04, 11:37 PM
#20
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You know, that port air solenoid port is so small (read- insignificant), we ought to be telling everybody to just disconnect the wiring connector from it, so it won't burn up & blow fuses & ECU's, like I've heard of some of them doing. Keep the connector tied up somewhere, in case it has to be reconnected for a "visual" on an emissions test...What do you think?
08-18-04, 10:28 PM
#22
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Evidently, it only affects us S4 guys...I figure instead of just accepting the fact that the sucker energizes & stays energized for another 20K miles when we hit 100K, 200K ,etc..., the guys with them still on their cars should just disconnect the damn thing at the connector out near the ACV to prevent any shorts & ECU meltdowns from occuring. It ain't like we need it energized anyway...