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power valve sticky?

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Old 09-26-2007 | 11:09 PM
  #41  
helps
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k that first hose you pulled off. what was that.
Old 09-26-2007 | 11:51 PM
  #42  
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That would be the hose to the 1-way valve and the surge tank. removing it causes an air leak which will cause problems.

Caped - Does you power valve open all the way, or just as far as you show in the video? the lever on mine moves a full 90 degrees.
Old 09-26-2007 | 11:58 PM
  #43  
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That would be the hose to the 1-way valve and the surge tank. removing it causes an air leak which will cause problems.
In Caped's video? .................... that first hose he pulled has nothing to do with the PV or the surge tank - its a vacuum tap for the cabin heating/cooling control.

The PV surge tank gets sucked on by a tube running to a vacuum port just under the PV solenoid.
Old 09-27-2007 | 06:17 AM
  #44  
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Originally Posted by LvR
In Caped's video? .................... that first hose he pulled has nothing to do with the PV or the surge tank - its a vacuum tap for the cabin heating/cooling control.

The PV surge tank gets sucked on by a tube running to a vacuum port just under the PV solenoid.
Oops.. you're right, I assumed that since he was messing with the PV actuator in the rest of the video, that he removed the vacuum hose in the first shot.
Although removing the surge tank hose would have the same effect on the engine's performance as removing the heater tap vacuum hose.
Old 09-27-2007 | 03:00 PM
  #45  
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the first hose i pulled off was just what LvR said. I pulled it off to show a classic vacuum leak stumble. Then i moved over to the power valve side of the engine.

the one way valve was the white disc thing that I couldn't get the hose off of haha. It was on too tight. but i found 2 cracks in my Power valve vacuum system (at the ends of 2 of the hoses) so i cut the tips off and put the hoses back in place.
Old 09-27-2007 | 03:01 PM
  #46  
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Originally Posted by sonicii
That would be the hose to the 1-way valve and the surge tank. removing it causes an air leak which will cause problems.

Caped - Does you power valve open all the way, or just as far as you show in the video? the lever on mine moves a full 90 degrees.
um.. i guess just what you see? i was in neutral so it's not like i had alot of time at WOT before it reached the 3500rpm cutoff point, and reclosed the valve. Maybe on a dyno i could see but in neutral, it juts spins up too quick.
Old 09-28-2007 | 06:48 AM
  #47  
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Originally Posted by capedcadaver
um.. i guess just what you see? i was in neutral so it's not like i had alot of time at WOT before it reached the 3500rpm cutoff point, and reclosed the valve. Maybe on a dyno i could see but in neutral, it juts spins up too quick.

Possibly, but on mine, it turns the full 90deg before it cuts out and returns. Can anyone else check what their PV does on the VG when revving the engine in neutral. I think mine was working similar to yours until it eventually stopped working all together, then after I repaired the internal rubber boot/baffle, it move the full 90 deg. Might be worth doing a vacuum test on yours just in case??

Last edited by sonicii; 09-28-2007 at 06:52 AM.
Old 09-28-2007 | 07:23 AM
  #48  
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Originally Posted by sonicii
Possibly, but on mine, it turns the full 90deg before it cuts out and returns. Can anyone else check what their PV does on the VG when revving the engine in neutral. I think mine was working similar to yours until it eventually stopped working all together, then after I repaired the internal rubber boot/baffle, it move the full 90 deg. Might be worth doing a vacuum test on yours just in case??
The actuator operates off of a sealed membrane - ie - applying vacuum from the vacuum surge tank through the PV solenoid valve can and must only result in a single outcome - full application of the vacuum signal and thus a full stroke of the PV through 90 degrees - there cannot possibly be a linear opening of the PV at all - its either on or off.

Now as to the description of how and when the ECU decides it needs to in fact close the PV and at exactly what intake flow level and rev setting that is supposed to happen is anybodies guess - depending on how fast you "flick" the throttle, the exact state of tune of the motor, wall thickness and quality of the vacuum tubes running to he actuator, inlet modifications (CAI etc), exhaust modifications, engine temperature, EGR, timing, under-drive/lighter pulleys/flywheel etc etc etc will all play a significant role in the response time of the motor and its ability to pick up speed, so its quite possible that all motors will show a different PV response to a blip on the throttle .................... IMO there can be no rule saying it must be like this or like that - there is simply too many variables involved apart from the ECU with a mind of its own.
Old 09-28-2007 | 10:27 AM
  #49  
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Originally Posted by LvR
The actuator operates off of a sealed membrane - ie - applying vacuum from the vacuum surge tank through the PV solenoid valve can and must only result in a single outcome - full application of the vacuum signal and thus a full stroke of the PV through 90 degrees - there cannot possibly be a linear opening of the PV at all - its either on or off.

Now as to the description of how and when the ECU decides it needs to in fact close the PV and at exactly what intake flow level and rev setting that is supposed to happen is anybodies guess - depending on how fast you "flick" the throttle, the exact state of tune of the motor, wall thickness and quality of the vacuum tubes running to he actuator, inlet modifications (CAI etc), exhaust modifications, engine temperature, EGR, timing, under-drive/lighter pulleys/flywheel etc etc etc will all play a significant role in the response time of the motor and its ability to pick up speed, so its quite possible that all motors will show a different PV response to a blip on the throttle .................... IMO there can be no rule saying it must be like this or like that - there is simply too many variables involved apart from the ECU with a mind of its own.
valve opens at 4000rpm or <50% throttle (or both..) so if I hit 4000RPM before the valve fully closes, then it's already going to open again. Plus i may be blipping the throttle so fast that i don't give it enough time to close. Or maybe my membrane in the actuator is torn and leaks a little, making the vacuum air pass through and not truly do its job.

Last edited by CapedCadaver; 09-28-2007 at 02:39 PM. Reason: stupid typos that i made during a brain fart.
Old 09-28-2007 | 10:39 AM
  #50  
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valve closes at 3500rpm or <50% throttle (or both..)
Out of interest only - where did you get that spec? - I must have missed it in the FSM
Old 09-28-2007 | 02:36 PM
  #51  
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Originally Posted by LvR
Out of interest only - where did you get that spec? - I must have missed it in the FSM
I got it out of the FSM alright. Just from the wrong part. 3400RPM is the EGR solenoid's key RPM. the PV actually actuates open at 4000RPM


^^^^fixed the post

Last edited by CapedCadaver; 09-28-2007 at 02:39 PM.
Old 09-29-2007 | 04:03 AM
  #52  
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then after I repaired the internal rubber boot/baffle,
So while checking fluid levels this AM, that comment of your suddenly rang a bell as my eye caught the PV actuator ........................ exactly how did you manage to "repair" that sealed (was yours not?) canister and funky membrane?
Old 10-01-2007 | 06:19 PM
  #53  
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Originally Posted by LvR
So while checking fluid levels this AM, that comment of your suddenly rang a bell as my eye caught the PV actuator ........................ exactly how did you manage to "repair" that sealed (was yours not?) canister and funky membrane?
Mine was sealed and was not easy to get apart. I had to grind the edges off as it is rolled and pressed together, I was able to get hold of a sheet of silicone rubber. I removed the old membrane, cut a hold in the new rubber and fixed the lever/spring to it, then reassembled the unit with the sililcone rubber hanging out the sides, held it in a vice, pressed the lever all the way in to streach the silicone rubber, trimmed the excess silicone and drilled holes around the edge of the casing and through the silicone, then used small screws and nuts on these holes to hold it all together.

If yours is faulty, and you can get hold of a good unit then don't bother with the repair, it is not very easy and doesn't look the best once it is back in the car, although it does work.
I can get some photos of mine if you like.
Old 10-01-2007 | 08:33 PM
  #54  
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Originally Posted by sonicii
I can get some photos of mine if you like.
yeah let's see it
Old 10-01-2007 | 09:58 PM
  #55  
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here you go. Unfortunately I don't have any images of it when it was apart. As you can see, it doesn't look the prettiest, but does the job..



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