Max_Gator

For those of you that have been following the saga . . . today, the dealer is FINALLY replacing a substantial portion of my variable intake system. Specifically, the plenum (intake collector).

I got a chance to look at the new one this morning and understand why they could never diagnose the problem: The collector is one piece from the factory and the "variable" portion of the intake - the valves that open and close - are inside the collector and can't be accessed.

To get to the valves, you'd have to cut the plenum open.

So, if i've correctly diagnosed the problem, my car ought to get its 30hp back this afternoon.

This is the original thread:

http://forums.maxima.org/showthread.php?threadid=99861

dwapenyi

iTrader: (3)

Good going

DW

maxfreak_98

Looks like your persistance is finally going to pay off.

Time for another "60 roll"....I'm sure I'll be looking at your tailights this time

Terry

Y2KevSE

iTrader: (13)

Finally...

Enjoy the 30 whp.

SteVTEC

sweet !!!

I thought you were trying to sell the car though...

Guest

That was the only thing left over, right ?
Guess we'll see on the next dyno run.

-Good Luck.

Max_Gator

Yeah, we'll see on the dyno but I ought to be able to tell when I drive it today.

If it ain't that, I don't know what it is.

By the way, they fired the ******* service advisor that I had to deal with - service manager is still there, though.

Terry - I'm not so sure about seeing my taillights - but hopefully, you won't be able to pull away from me over 100 anymore!

IceY2K1

iTrader: (3)

Good job!

Can't wait to see the "new" dyno.

MAX2000JP

Good Job!

Hopefully this is the fix for your problem. If it is I will be very happy. Let us know how it goes.

BTW...Can you provide me with a link to you Dyno Charts?

Max_Gator

I believe IT IS FIXED. I can feel the car really pull hard when it gets to 6k+. I did numerous runs, but it was raining. I'll try again tonight by comparing VIAS connected and disconnected. Hopefully, my butt dyno is not off - I do not think it is. Hell, if I can chirp the tires in the shift from 1st to 2nd on my Pilot sports - that'll be proof right there since I haven't been able to do so.

Dyno charts are back in my sig.

I can now mod away!! (Of course, I have to start by fixing my Cattman Y pipe )

Guest

Amen. Did they rip open your old intake manifold to see what happened ?

MAX2000JP

Thanks for the help. I just printed your charts and am gonna bring them in with my dyno. Can you PM me some information/names that helped you through the process? Thanks a lot!

CIRCO

iTrader: (1)

Max_Gator is it just me or is your link to the Dynos broken?

Max_Gator

LOL. No, they won't give me the part.

I've asked them if they are going to do it and the mgr says "I dunno."

They don't want to know

Max_Gator

fixed now

Max_Gator

Make sure you use ONLY the stock vs. malfunctioning vias.

DO NOT USE the one with the mods on it - I don't want the dynos with mods to go to Nissan.

Guest

At least the theory turned out right, but I would like to know what failed. Was it the butterfly assembly or was it the MAP switch to activate it, I'm so tempted to open mine up to see, but don't wanna chance it breaking. Even if I have the schematics in front of me, I don't see where it can fail. Imagine all it was; was a loose hose to the MAP switch ?

I'm gonna ziptie mine on now.

Max_Gator

You cannot open it up without destroying it. It is one piece molded plastic about 12"x8" with one end taking in air and the other directly sitting on the intake manifold. You can't even see the butterflies.

I can guarantee it was the butterfly assembly. All the tests I did confirmed that the actuation system was working. Once you can see the actuator on the collector spin when the car hits 5k rpms, the only possible problem is a mechanical problem with the butterfly system inside the intake collector. This was not a loose hose.

As for schematics, the ESM doesn't provide anything but maybe you have access to it.

Guest

Gator, it's Hogan(yo_its_ok.) I was looking at it, and I find it hard for the butterfly assembly to "malfunction", but as long as problem is fixed, then amen.
How many others had this problem ? There should be a campaign from Nissan to discover how and why this happened ?

Max_Gator

You can't be Hogan - he's banned.

Do you have a schematic of it? I'd love to see it since the ESM really doesn't give a specific diagram of the butterflys.

You have hit on the very reason that it was so hard for Nissan to accept that I was having this problem. The plenum/intake collector is one piece. No one can even get to the butterflys, let alone diagnose a problem with them. That's why the ESM only gives a check for the actuator system.

Somehow, mechanical failure occurred inside that collector.

As far as I know, I'm the only one to have had this problem - at least that's what the regional rep said.

The incidence will be low since only people who push/test their cars will notice it - and then still it will probably only be those with 5spds.

Guest

LoL, banned, but still around to post up "good" things, no more "bad" things. Give me your shipping address, cause faxes suck, and scanning sux too. The print is very fine, and I can easily get multiple copies.
From our emails, it was the only thing left to point a finger at, and considering the ITI on the SR20DET failed, it was something similar, especially when you "test and tune" your vehicle alot.
Hmm, which regoin are you from ? Time to give a few calls to the Techs out in Gardena to find out what happened.
Some others have lost 30hp as well ? I just forgot who ?
Think it could be related ?

Max_Gator

Went to the track to test the car all stock, all I can say is interesting. Temp ranged from 75-85 according to my display (with decent humidity).

On the way up, I raced Terry (98 5spd with all bolt ons - with his girl in his car too) and fared better than I did last time with y/si/udp. We ran from 60 mph several times and he'd always get a jump then I'd reel him in a bit at the top of 3rd and then at the top of 4th. Didn't really get all the way to the top of 4th so couldn't tell how well I would do. All I can say is that Terry will beat a stock 5th gen from 60 through 100 at least.

That made me think I was all the way back. The track made me less certain.

First two runs, I got a great holeshot on Terry (.5xx) but then missed third - Argh. Terry even had the time shack guy giving me a hard time!! Don't think I beat him all day.

Best I ran with my vias connected was with 2.26 and 2.22 60' times - 15.2x @ 90.5mph. It was hot and one of those runs was the third consecutive run. At the end of the day - after much waiting, I ran with the Vias disconnected with a 2.21 60' - 15.39 @ low 88mph. I'll scan the plots. On the vias connected runs, I was 72mph at the 1/8. On the vias off I was 68 mph.

The mph was less than I recall running stock before and with a 2.22, I ought to be doing better than 15.2. However, I couldn't find my old stock results - so I searched on the org and found I did 15.1 @ 92mph when I first went to the track - it was nice and cool then. When I added the y/si, I went 94mph. So, I'm not sure if it was just the heat that kept my mph down.

Also,I noticed what appears to be an air leak in the variable intake area - sounds like it is coming from the spot where the manifold and the collector meet. When I hit the throttle a bit, it gives a quick squeaky sound very similar to the Stillen intake. I can hear what I think is a constant hissing leak.

I think I'll get that leak run-down before I put it back on the dyno. Then I'll post the dyno numbers.

MAX2000JP

Sounds like your car is fixed now! That leak probably held you back a little. It will be interesting to see your new dyno's

Max_Gator

Timeslips:

Vias Off is number 4:

http://web.tampabay.rr.com/maxgator/420times4.jpg

chinaonnitrous1

iTrader: (12)

hmmmmm sorry to bring this back..but with the VIAS off...could you rev past 5000rpm..cuz im having an issue with my 2k2..my thread about my 2k2 power loss

Max_Gator

yes can rev and drive just like normal. only difference the vias makes on the car is it changes the path/wavelength of the air going in.

I don't know much about the 2k2 vias.

2000MilkedMax

iTrader: (8)

Ive been having the same prob, but I was brushing it off in my head. After 5k on the highway my car wont pull for **** and then I have to wait till it shifts. But I been trying to find some pictures of where exactly is the vias, how do I disconnect it to test it, and If there is a fuse for it where is it? I was looking in the haynes manual but in there it seems as if it doesnt exhist.

Max_Gator

If you look at your intake manifold (the black plastic piece on top of your engine) on the driver's side towards the front of the intake manifold, you should be able to locate a small rectangular black box about 2"x4". That is what controls the VIAS.

Picture if you will that there is a rod running through the intake manifold from driver's to passenger side of the car. Attached to this rod are butterflys. the end point of the rod is the black box.

If you look underneath the box and toward the back of it you should see a piece of curved metal (L shaped) that sticks out. This is the rod.

To check to see if your vias is working at all, you need to rev the car in neutral above 5k and watch to see if this rod flips. You can either have someone in the car to rev or you can just push the throttle under the hood yourself until the rod moves or the fuel is cut.

That is the diagnostic performed by Nissan. But, as in my case it is possible that even though that works - the butterflys don't move inside. In that case, it is much more difficult to establish there is a problem because Nissan has no test for that problem.

The only thing you can do is run against a similarly equipped maxima above 5k with the other car's vias on and with it off. If you get different results, then you have a problem. To turn the vias off there is a plug below the black box. Just disconnect it.

2000MilkedMax

iTrader: (8)

I disconnected it and took it for a run down the highway then got off some exits down and reconnected it and it feels exactly the same. It feels like it looses power at 5k rather than pull to 5.5k. I only could get to 5k in 2nd and 3rd but I thought all this time it was bc I needed a Y-pipe or something. Now since i cancelled my extended warrenty like an ***, I have to call my mechanic that works at nissan to see how much he could get me a new one for, how much do they cost regularly?

Max_Gator

What do you mean you could only get to 5k in 2nd and 3rd?? Are you saying your car won't go beyond 5k if you leave it in 2nd or are you saying your tranny shifts at 5k but not 5.5k.

Right now, I'm not sure you've diagnosed a problem.

2000MilkedMax

iTrader: (8)

Beyond 5k the engine is just screaming but not pulling as hard as it was about 4k-4.5k, I ran it in 2nd up to about 6.3k taping the rev limiter once. I meant I didnt have enough room to test 4th to over 5k.

spirilis

iTrader: (2)

Interesting, I noticed my Maxima really sucks *** with low-end torque so I might have to find this L-shaped rod and check mine out. Actually, when I bought it, 1 of the vacuum hoses (the one on the left, looking at the VIAS "black box") was disconnected. Drove it home the other week, opened the hood to peek at Nissan's wonderful engineering, and noticed 2 vacuum hoses disconnected (that's one of them, the other I have NO IDEA where it goes... it's currently sitting open near the "BOOST SENSOR" for now... has kind've a thick insulation to it?)
Makes me wonder what the previous owners (or their mechanics) did to that thing...

Max_Gator

I posted on another thread that there is a tsb for low end power loss resulting from the vacuum hose going to the vias being kinked. When there is no vacuum, the intake manifold is acting as it would above 5k which results in power loss.

spirilis

iTrader: (2)

I actually saw the TSB in my AlldataDIY site (I subscribed to alldatadiy for my '00 Maxima, if anyone needs diagrams/etc. ask me )
I *think* I got the right vacuum hose when I peeked under the hood yesterday, and it looks like the hose was fine (the hose looked pretty new, actually...)

I have another vacuum hose that's DISCONNECTED and I don't know where it goes! Almost looks like the other end goes down to the transaxle... I have a decent digital camera so I'll take a pic of it soon.

dwapenyi

iTrader: (3)

If you're standing in front of the car facing the engine, is this hose like somewhat behind the ram air scoop, to the right of the forward cylinder head? It points towards the battery and then curves down, as if to spill whatever its contents down onto the tranny?

DW

spirilis

iTrader: (2)

Yep, that's it. Although mine's on the left side of the ram scoop for some reason (I might have pulled it over there to get a better look at it, I don't remember ). The open-end of the hose looks like it has some kind of thicker insulation around it. Any idea what this is??

njmaxseltd

iTrader: (19)

Vent hose for your tranny. It's supposed to go nowhere.

dwapenyi

iTrader: (3)

NJMAX apparently identified it. I never did, but it did freak me out when I first got my car, too Then I looked at 2 other Maxima engine bays and found it on both. That made me see that it's normal for our engine.

DW

JKiMaxAC

just a question.. dose this apply to auto's to?? or just manual's???

Loe max

iTrader: (6)

This applies for all VQ30DE-K's

If your VI doesn't engage to its short runners above 5,200rpms, the sound is AWWWWWWWWWWWWWWFUL with an intake. It sounds like the paper element on the filter is going to rip and explode. I tried this experiment out by unplugging the plug located in the black canister box.

If you disconnect the vacuum hose to have VI in its short runners all the time, the intake noise is more mechanical and less boomy. There is no change in noise at switchover, and there is no change in noise when the automagic shifts into the next gear. You also don't get that 2,800rpm rush, instead the rush occurs at or near 4,600rpms

I have a picture of the black canister box if anyone wants to drop me an email or IM me