spirilis

iTrader: (2)

Alright, well, IceY2K1 (and DAVEB) were right. My VIAS is working. The stopwatch doesn't lie

I really should follow up with some tests in 3rd gear. However, I don't have any roads very local to here where I can get her up that high, so I did it in 2nd gear.

Both trials-- 2nd gear, 40MPH to Fuel Cut. Accelerated gently in 2nd to 40MPH, then simultaneously slammed the pedal and hit the start/stop button, hitting the start/stop button the moment I felt the fuel cut.
Same stretch of road for both trials, same outside temperature.

Trial #1: VIAS control solenoid CONNECTED
Trial #2: VIAS control solenoid DISCONNECTED

Trial #1 time: 5.83 seconds, 40-fuel cut
Trial #2 time: 6.37 seconds, 40-fuel cut

I did notice trial #2, with the VIAS disabled, the top-end does sound a little more "boggy". It was evident especially since I had just experienced that situation with the VIAS connected only 5-10 minutes before.

I would have done more than 2 trials, but I didn't because I think that sorta tells all... although the 0.54 second difference could be chalked up to error, I was pretty diligent about making sure my stopwatch button timing was consistent.

spirilis

iTrader: (2)

Also, beforehand I did the no-load rev-up test with a flashlight pointed at the VIAS actuator... the Power Valve does indeed rotate back and forth when you rev up/down/up/down the engine under no load.

Larrio

iTrader: (10)

the power valve test of whether the valve rotates when the engine is under no load is deceiving.

considering that mine does the same, but the VIAS doesn't work. I can't feel the difference when driving, but dynos don't lie.

spirilis

iTrader: (2)

True, but mine's backed by a (somewhat minimal, could be enhanced) road test now. I intend to do some more tests later on when I have the opportunity (and a stretch of road where I can get it up to ~90-100MPH in 3rd), but until then I'm sticking with my results.

SR20DEN

iTrader: (7)

Guys I answered this question already. Look at post #30 in this thread.

Larrio

iTrader: (10)

yea, I missed that. Bottom of page 1

mad2kmax

iTrader: (4)

Alright guys, SR20DEN has already answered this question, but I will try to elaborate the best that I can.

The L-arm is under the black box that is connected directly to the intake manifold. Most of us already know this. The power valve, rod, whatever you want to call it, looks like this, l-l-l-l-l-l-. Again, most of this already know this because of Ice's pictures. The part that is MALFUNTIONING is internal, that's why we have been saying that the visual test is useless, unless you have a faulty vacuum. The part that is failing is the connecting rod from the external mechanism to the actual power valve/rod. It looks like this: l-l-l-l-l-l---]-.
This (]) being the barrier from internal to external. This little connecting rod is about as thick as the lead in a wooden pencil, seriously. When I studied the broken piece, it looked to me like the metal was brittle to begin with, b/c it didn't look like it twisted at all before it broke, it just snapped. That is why I have previously said that it was a very poor design. I'm would be supprised if mine lasted more that 10k miles. I hope that this clears up any questions as to what was malfunctioning in my engine. If you have further inquires, ask and I will try to explain in simpler terms.

Mad2kmax

IceY2K1

iTrader: (3)

A picture is worth a THOUSAND words...LOL!

So it's on the backside of this collar?

mad2kmax

iTrader: (4)

yes. from the looks of the picture, the collar was still on the valve. the little metal piece that you see in the center part of that picture is what had broken off the collar. The center part was no longer part of the collar and was grinding on the collar, producing the metal shavings.

IceY2K1

iTrader: (3)

THANK YOU~!

Boys and girls...this means you DON'T need a whole manifold...just the VIAS box end, which thanks to Nissan you can't JUST order. However, I'm going to double check that.

So, if you pull off the VIAS box and manually turn the L-rod, you'll know it's working or not if this collar turns.

mad2kmax

iTrader: (4)

This is my advice: do the visual check to make sure that it's not something with the vacuums; i.e. have someone rev the engine past 5k and you look at the L-rod/arm and make sure that it is active. Then, disassemble the vias box and see if the connecting rod is still intact with the power rod/valve. Test this by turning the L-arm/rod manually and see if the power rod/valve turns with it, after disassembly and you can see both internal and external.

spirilis

iTrader: (2)

Hmm, that axle piece which is turned by the L-rod appeared to me to be removable... i.e. if you could unhook the vacuum actuator's rod from it, there was a nut holding it in place.
I wonder if you could find a replacement piece somehow at a hardware store?

SR20DEN

iTrader: (7)

post # 88

spirilis

iTrader: (2)

Ahhah

You know the thread is getting too long when we keep forgetting about posts

Oh well, at least I now know the VIAS is not a problem for me

Galo

Alex....there's a TSB for this...been around for a long time....I had it done years ago.. I dont remember the TSB number but I've seen it around in various TSB lists that have been circulated here.

It makes the part-throttle off-the-gas to on-the-gas transition much smoother...

IceY2K1

iTrader: (3)

I've already had that done....not much difference and some negative side-effects to boot.

IceY2K1

iTrader: (3)

I took it all apart down to the shaft/collar last night, however one part I'd have to bend/force out the prongs, ie it's pressed in, so I stopped.

Once Larry gets his replaced and sends it to me, I'll disassemble it the rest of the way.

ChromeSE5

iTrader: (3)

So when VIAS isn't working acceleration should feel linear... and won't have that v-tech/vvt-i feel to right?

spirilis

iTrader: (2)

In my observations, the acceleration should feel smooth and linear with the VIAS working. Without the VIAS working, the engine appears to "bog down" after 5000 RPM.

IceY2K1

iTrader: (3)

Can you describe how the RPM on the tach change?

I've been studying mine for the past week or so and it "seems" to accelerate at a faster rate from 5000rpm to redline. However, I currently have the stock intake on so I can't hear much sound change.

NewLoveI30

I wish I had the Balz to take mine apart (I think it works). Maybe we could design a better axel for the valve. It is my understanding that the axel is what breaks. Is this correct, or is it where the axel and that key shaped collar meet that is wearing out?

spirilis

iTrader: (2)

It *might* move a little faster, but certainly not by much. Certainly not enough to catch your attention.

I'm using the stock intake but without ramscoop, and a K&N panel filter in the airbox.

IceY2K1

iTrader: (3)

Behind the key shaped collar on the left:

IceY2K1

iTrader: (3)

Damn it.

As soon as I find bolts to replace the STUPID screws, I'm pulling it then.

spirilis

iTrader: (2)

Big screwdriver with a rather large philips head bit, pushing its end hard into the screw with a pair of channel-lock pliers to twist the screwdriver... ahhhhh yes no stripped screws

SR20DEN

iTrader: (7)

IIRC you use four M6 x 1.00 x 20mm (10mm head)bolts for the actuator side and two M5 x 0.8 x 14mm (8mm head) bolts for the removal side.

And don't forget two M5 washers and four M7 washers.

IceY2K1

iTrader: (3)

Thanks...you just saved me an hour at Home Depot trying to find what I need.

Larrio

iTrader: (10)

Just called my nissan dealership today

intake manifold is covered underneath 7yr/70k mile warranty. Which is good for me, but too bad I didn't know earlier

NewLoveI30

Ahhhhh, So the "power valve is one piece! I thought from the descriptions that is had an undersized metal rod going through the middle, and that is what ws breaking.

So if the problem is on the back of the collar then what is making the "metal shavings" INSIDE the IM. If I am not mistaken (again ) the back of that collar is outside of the intake runners. That is the only thing I was worried about. I didnt want to be sucking metal pieces into my cyinders.

Thanks for the pic Ice.

Loe max

iTrader: (6)

If your like me and have a sensative ear and feet, their is a slightly more course sound from the engine as well as slight vibrations in the gas pedal after 5K when the VI plug is disconnected. The revs dont pick up as fast after 5,000rpms in second gear, 1st gear doesn't make a noticable difference. Another thing is when your at WOT and you notice a spike in power (shove in the back from the power) after the 1-2shift vs. 1st gear at redline, thats another indication that your VI isn't functioning.

spirilis

iTrader: (2)

Yep, with it disconnected you can hear/feel something that sounds like it's "bogging"... manifests itself as slight vibrations and sounds.

Max_Gator

Oh, it is covered all right . . . but that's not the problem.

The problem is that the only diagnostic for the VIAS in the FSM is checking to see if the actuator moves. THAT IS IT. As a result, they check that and tell you that nothing is wrong.

With all the info in this thread, though, that might change since you can tell them exactly how to pull it apart to see if it is working.

They replaced my entire intake manifold. When they showed me the intake manifold they told me the entire mechanism was sealed inside. That was either ignorance on the mechanic's part (entirely possible) or a flat out lie to cover up what they knew was a problem.

Max_Gator

It can be difficult to tell from just seat of the pants. The way I could tell was that the motor sounded like it was just making too much noise.

In fact, the very first time I tested mine against another car I still thought it was working because we only tested 1st and 2nd.

Honestly, the only way to tell for sure is to test the car with vias connected and disconnected. And I think the only really reliable ways of doing that are (aside from a dyno):

1. Several runs at the track - so that you are using a certain fixed distance and reliable timing method. I think this only works if you have run your car at the track often enough to drive it consistently. The difference is probably only .2 and 2mph. If you haven't run it enough, you won't be able to tell.

2. Runs against another vehicle - I believe this is the BEST way to tell. (Assuming that you have a closed course to run on since I would never suggest street racing). Do several 3rd gear runs from 5k rpms (so power valve is already on) to redline against another car - preferably a maxima but not necessary (whose driver drives exactly the same way in the same gear from the same rpms each time). You can coordinate with honks/hand signals or phones if you have earpieces. Do a couple with vias connected so you establish a consistent pattern. Then pull over, disconnect vias and do a few more that way. If the results are THE SAME - you have a problem.

I saw sprilis' test above and because of the gearing and timing variables, I think he should try #2 above. First, 2nd gear is VERY tough to tell the difference. I ran several times against an identical car and in 2nd we could barely see the difference. Second, the process of hitting the stopwatch while driving can easily lead to several .10s variation. Third, with a run against another car, you've got two people to provide an opinion and evaluate the differences. I can easily see the difference he got being accounted for by the variations - but perhaps he's more consistent than I could be.

spirilis

iTrader: (2)

I won't be able to run against another vehicle... I simply do not have access to the resources to do that (nobody nearby who would participate in that kind of run, and nowhere safe for 2 people to do it side-by-side). So I am stuck with the timing method--stopwatch, track, dyno, whatever (track & dyno I really have to go out of my way to do... the stopwatch method is preferable, although I'm still pretty confident that my VIAS is working now that I've compared them in succession)

BlackBIRDVQ

iTrader: (15)

I just inspected mine and I turned the VIAS on at 2K RPM and the car felt like shizzo, then I turned it off completly and car didn't move as it should have. I need to go dyno my car again, when stock it put down 199.3WHP and now its got every single bolt on, even a flywheel that I don't see people having. I'm shooting for 220WHP minimum... Hmm I will dyno in a week.

IceY2K1

iTrader: (3)

I say 3rd gear is best, since 1st/2nd is too short and reaction time can muddy the results.

If you can get 2-3 consistent stopwatch runs starting with your CC set at 60mph to redline, then stop disconnect the VIAS solenoid plug and get 2-3 more consistent runs. You're good. But as **** as I am, I'd reconnect it, and do 2-3 more runs to make sure it's not just heat soak.

So, set cruise control at 60mph in 3rd:
1)2-3 60-100mph w/ON
2)2-3 60-100mph w/OFF
3)2-3 60-100mph w/ON

Assuming you're manual...not sure what speeds/method would be best for an auto due to a 130mph 3rd gear and tranny downshift issue below XXXXrpm. So, 2nd gear at ~4000rpm manually shifted into 2nd to redline maybe?

Max_Gator

How did you turn the Vias on at 2k rpms? Did you find a way to hookup a switch?

If you put down 199.3 whp stock then you have a monster. (That is, of course, if the 199.3 was SAE corrected and the redline spike was taken out.)

Of course, if you take out SAE correction, my best recent dyno was 213.63 hp/ 200.92 tq!

spirilis

iTrader: (2)

Yeah, I agree, 3rd gear runs should give a better idea. Now the problem is... finding a stretch of road around here where I can do that. I'll definitely have to make a 2 hour event out of this

SR20DEN

iTrader: (7)

Side stepping the clutch on the dyno doesn't count.

IceY2K1

iTrader: (3)

All you need to do is ground the VIAS solenoid, so a simple switch would do it.