AsthmaMax11

iTrader: (3)

Well I finally proved this at the Dyno last night. It opens everytime in neutral but not a single time in the 6 runs I made last night at the Dyno.
Who else has had this problem and what did it end up being?
To be honest, if I don't get good feedback in the next day I'm putting the USIM back on.


thanks

96sleeper

iTrader: (4)

Mine did that on the dyno, it was the harlan rpm switch. I switched to the summit switch and never had another problem. If you already have the summit switch, it could be your vacuum source tank. The car makes vacuum at idle/no load, so maybe you have something backwards.

I30tMikeD

iTrader: (8)

I had the problem two seperate times. First it was my harlan switch, second it was the internal check valve in vacuum canister. These problems pop up all the time on the forums, and 99% of the time it is either a bad harlan switch or a vacuum problem.

AsthmaMax11

iTrader: (3)

ok. Thank you for the useful info. I am glad Mike posted because I remember him saying something about it a few weeks ago.

so if the internal check valve in the vacuum canister is the problem, will I just have to replace the vacuum canister? I will mess with it some more but it is really irritating me.

DandyMax

iTrader: (7)

If you need an rpm switch I have a Summit available... used for about 6 months but works perfectly and is in excellent shape.

Whitemax

PM me with a price for it. I'll be needing one hopefully soon....

I30tMikeD

iTrader: (8)

No, you can just buy a $1 check valve and run it inline with the canister, some thing as having one inside.

Try two things. First let the car run for a minute. Turn it off and remove the vacuum hose at the canister that goes to the solenoid. You shoud get a rush of air from the stored vacuum. If you don't then you know the canister is not holding vacuum.

Or remove the canister and try blowing through the ports for the vaccum hoses. Air should only be able to travel one way. Try shaking it a bit before each time you blow through it.

Since the engine sees vacuum at idle the MEVI will work, but under load on a dyno there is no vacuum so if the canister is not storing it then it will not open.

I am sure this is your issue. I have been through this stuff many times.

Zack342

iTrader: (89)

I will have to agree with Mike here. When i dynoed a couple weeks ago on some runs my MEVI would not open underload....My check valve on my vacuum canister wasn't working properly. I would try replacing the check valves then check the RPM switch csince the check valves are so cheap. I to 2 and run them in line in case one ever fails.

Nealoc187

iTrader: (23)

It's happened to me too. It's the checkvalve.

00SEMAX19

iTrader: (4)

Been here for a while and here about it all the time but what is a MEVI? Sorry for the ignorance

Nealoc187

iTrader: (23)

You're joking right? Check out the 4th gen stickies or just search there's probably 200 threads about MEVI... heck there's probably 50 of them in this forum alone.

00SEMAX19

iTrader: (4)

Well Neo, At least I didn't post a new thread on this.

I've read about 20 pages worth of crap on the mevi not working right an is it better than the 00vi. Vacuum canisters Rpm switches, bla bla.

I know it has something to do with variable intake, Like the vias in my 00 (RIP) but Is this just the same flap that I have in my intake? Is it aftermarket?

I don't care if it's good, better or worse than something else, or what, but I am sick of hearing about this damn thing and not completely understanding wtf it is.

Please just make it simple and explain, maby just give a link to an advertisement for the thing or something.

Yes I know there are about 200 threads on this but I've read about 20 worthless ones. Don't make me **** everybody off and start a stupid thread that everybody is going to Flame at.

Nealoc187

iTrader: (23)

Check out the 4th gen FAQ sticky thread at the top of the 4th gen forum. It explains it fully.

I30tMikeD

iTrader: (8)

http://forums.maxima.org/showthread.php?t=217001

AsthmaMax11

iTrader: (3)

Ok here's the progress I made and the things I have learned this weekend.

One of the ports on my Canister broke off a few weeks ago. The hose will still sorta connect to it but it comes loose very easily. At the same time when I opened the MEVI at idle today it wouldn't open all of the way most of the time. This leads me to believe I don't have enough Vacuum to open the MEVI all the way even at idle. (duh.) I'm going to order another canister tomorrow.

I bought a one way check valve from Advanced Auto parts but I still don't get what you guys are saying about putting it inline with the Canister...

So the hoses go: Manifold Vacuum > Check Valve > Vacuum Canister > Solenoid > Manifold actuator.

I replaced the white check valve and I actually got the MEVI to open a few times on the way to my GF's place but I still feel it isn't staying open.

My Summit switch works fine btw. I think I almost have this!

deezo

iTrader: (3)

Put it on the hose between the actuator and the canister.

Nealoc187

iTrader: (23)

Actually between the vacuum source and the canister is where you want it.

Like this...

AsthmaMax11

iTrader: (3)

Wow. I think that did it. Just went for a test drive and the car hauled butt compared to before!!! Thanks alot for the pics man. You guys just saved me alot of time and money. You guys rock

Since one of the ports on the canister is broken should I just buy another one or try to sleeve something on there?

Nealoc187

iTrader: (23)

Do you mean the nipple is broken? Or are you just referring to the fact that the built in check valve is not working? If you mean the latter, don't worry about it. As long as you have the extra check valve there (and it's working) you will be fine. If you mean the thing is physically broken off or something it might just be easier to get a new one. They are only like $10.

Dave B

As taken from the Bijangxe post in the 4th gen section, here's my response:

I suggest getting the Harlan RPM switch and a toggle switch. Mount the RPM switch in the cabin and on the lower dashboard so you'll know when the Harlan flakes out (LED will flash continously). Flip the toggle switch a couple times rapidly and the Harlan resets itself , even without restarting the car.

I think there are FAR more Summit switches out there that aren't working. The fact that people can't hear the induction noise change when the valves open is very suspect. With an intake and the MEVI, the induction noise change is as loud as a Honda hitting the VTEC lob. At least in my car it was.

AsthmaMax11

iTrader: (3)

yeh man the nipple itself is physically broken off. I put a bunch of gorilla glue in there and it seems to be sticking pretty well. (I ordered a new canister just in case too)


Dave,
I see your point about the toggle switch but at the same time I haven't heard of anyone else having problems with the Summit Switch. My green light comes on more than 90% of the time even when I am driving and when I first switched from the Harlan it was like night and day.

I30tMikeD

iTrader: (8)

Change that Canister.

Dave B

For the past year, I've been constantly reading about people having issues with the MEVI setups and the Summit RPM is used in nearly all of those setups. I too got the green light and verified that the valves open with the hood up. At the track it was clear the thing wasn't working hence the reason my car was .3 and 3mph slower. There was no change in induction noise with the Summit switch either. No change in noise = not working.

I ran the Harlan for 1 year before the Summit switch and it worked 90%+ of the time. I then bought the Summit switch because I had read it was perfect. Truth be told, it was worse than my Harlan switch. After one months use, I went back to my Harlan setup for another year until I sold the car. I was one of the few that actually tested my car quite a bit on the track. Most people on the site don't test under a real timing device therefore they can't gauge their car's performance. I have a strong hunch a lot of these Summit switches are not working. The reason I believe this is because so few people with the MEVI report an induction noise change when the butterflys open. I could hear the induction noise change on my MEVI and I can hear it on all the 5th/6th gen Maximas and Altima S (QR25) I rent for work. My old MEVI is now on a local 96 SE auto and it works perfectly. He owner has told it's never failed once since I installed it 8 months ago.

AsthmaMax11

iTrader: (3)

Well after reading that I am glad I saved my harlan switch. So would you say that all the "hype" about the Summit switch is due to the green light coming on everytime? I mean you can't really say someone is having problems with the Summit until they switch to something else and it works better. I think we have two surefire options: use the ECU off the Maximas that comes with the MEVI stock or buy a VAFC.

I can usually tell if the VI is opening by feel. I mean the car feels ALOT slower when it doesn't have that extra 30-40 hp after 5k.

NmexMAX

iTrader: (22)

Stephen and Dave B have had nothing but good with the Harlan ..

A few of us (myself included) have had bad experiences with it.

I wqent through 2 of them, when finally I switched to Summit, and it has worked 90% of the time, and when it doesn't work, it does not require an entire reset procedure. I'm rpetty sure the times it doesn;t work, it's vacuum related. But that Harlan flakes out, requires a reset and that gets annoying.

When the Summit doesn't work, ust let off the throttle, to come back below the set rpm, and go WOT again, and there's the resonance sound change and verification that it's working and doesn't requrie a reset.

deezo

iTrader: (3)

I'm going to try the MSD Switch that Jime is using when I get the cash.

abci30

iTrader: (11)

i had the harlan switch on for a while but then i guess i fried it or something. Everything was hooked up right but it would not open my mevi at the set rpm. The lights went on to let me know the thing was powered but the light never came on when the rpm was reached so i just got a summit switch. When i tested it, the switch worked fine. Hope i don't get any problems with the summit switch cause Last that i've heard they don't make Harlan switches anymore.

98SEBlackMax

iTrader: (9)

How many of you guys have properly soldered the wires of the Summit switch on install? And crimping them is not the same as soldering. Im having this theory people wire wrap stuff together and this maybe the problem. I always solder and heat shrink my work and I have never had a Summit switch flake out on me.

deezo

iTrader: (3)

I actually thought of doing that.

I30tMikeD

iTrader: (8)

I respectfully disagree on all points

DandyMax

iTrader: (7)

I do the same thing - it's always worth it to take the time to do the wiring properly. Saves lots of time and headaches later.

When I still had it hooked up, I've never had my Summit switch not work. And that's not just based on watching an LED but looking under the hood and seeing the VIAS rod activate time and again.

Nealoc187

iTrader: (23)

Same.

I've never had the Summit switch not work. I THOUGHT it was not working at one point until I realized it was my check valve that was causing my MEVI not to open, not the Summit switch.

Also Dave you often like to mention the noise change as a clear cut indication that the MEVI is working. As I've said before, and I'll say again, I have never once, not ONCE heard my MEVI open up. Never. By the time I hit 7000rpms I could tell from the sound of the engine if it had opened, but at the point of opening, I have never heard it open. And I'm not hard of hearing either, I've actually got excellent hearing as per my Aviation Medical Examiner.

So basically Dave and I disagree on all points, and yet both of us have LOADS of experience with what we are talking about, interesting huh?

Finally, watching your MEVI open while you are sitting in your driveway when you neutral rev it up to 5400rpm does NOT NOT NOT mean the MEVI is opening under load. Free revving to 5400rpm in your driveway, you are still creating vacuum. If you have a totally faulty vac canister or checkvalve, you can still get your MEVI to open in neutral. With a faulty canister/valve, when you hit 5400rpm, your engine is still creating vacuum and the MANIFOLD vacuum, sucking all the way through your vac canister and faulty checkvalve, is what is causing the MEVI to open, NOT the vacuum stored in your vac cansiter. This has absolutely NOTHING to do with your summit switch or harlan switch, and is completely and utterly a check valve problem.

I didn't realize this for a while, which is why I couldn't figure out why the MEVI would open when I tested it, but would not open when I was driving. Then I realized it, got an inline check valve, and never had a single problem with my MEVI not activating again.

I'd be willing to bet a large sum of money that THIS is why many people think their RPM switch is messed up, when it actually has zero to do with their RPM switch.

This is a different problem than many report with the harlan switch though, which is when the switch itself wigs out and starts flashing an error and refuses to work at all (no MEVI activation in neutral OR under load) until you shut off the car and restart it.

96sleeper

iTrader: (4)

+1 on all accounts. I can never hear my MEVI open (no sound change, but I do have loud intake/exhaust), but when it doesn't open you can definately hear the strain of the engine. Mine has never messed up once I switched to the summit switch.

deezo

iTrader: (3)

I installed a new one when I put mine on and sometimes the VI doesn't feel like it's opening. Maybe its just me but I did notice the difference in power when I mistakenly had the RPM switch open up at 6000. You do feel the kick in power once it opens.

I'm going to solder all of my connections tomorrow before i ht the track.

That was funny Neal....

"I've actually got excellent hearing as per my Aviation Medical Examiner."

Dave B

Things must be different here in Kansas City because I could clearly hear the switchover on my 96, the 96 auto I installed my old MEVI on, and also on BSwithTF's (Travis) 95 GXE auto. The switchover sound was loud as hell with the hood up on my car and Travis' when we were at the dyno years ago. I'm not joking when I say that the induction noise sounded very much like a stock 99 Civic Si hitting the big cam lobes. I can also clearly hear the switchover sound on the QR25 and VQ35 motors I drive for work. These motors have the same exact style intake manifold setup (resonance chamber) that the MEVI has so I don't know why it wouldn't make a noise at the switchover if it's actually working right.

I also know that sound of when the valves haven't opened and the engine revs past 5500rpms. The sound is strained with lots of resonating. The intake gets kind of farty and it's clear that once above 6200rpm, you're not accelerating. That was one of two indications to me that it wasn't working. The other indication was the flash led on the Harlan switch. When the MEVI is working, the overall sound is smooth and never sounds strained.

I too have great ears seeing that I have to get a full blown $1,500 physical every year for work which includes a 15-minute hearing test

That's what's so frustrating to me and probably most everyone else. It only adds to the confusion of why setups work and others don't. Giving advice doesn't mean it will definitely correct the problem when it comes to this frustrating mod.

My vacuum canister had a check valve in it and I verified it to work on every occasion I tested it. I also ran an inline check valve from the 1st week I installed MEVI just for safe measure. The canister always held air.

With a toggle switch hooked up inline with the Harlan switch ground wire, when the switch flaked out, you simply flipped the toggle switch twice and the Harlan reset itself. There was never a need a turn the engine off.

mitch33x

iTrader: (5)

I've had the VI and Summit switch set to 5k for over a year now, I have never heard a change in the tone of the intake sound.

Zack342

iTrader: (89)

Other than me seeing my tach needle move like its on fire i wouldn't know

Dave B

Yesterday I sold my 225/50R15 BFG DRs to grey99max (Harold). His 99 SE auto has nitrous, all the bolt-ons, and the MEVI. Something that caught my eye was that he didn't have vacuum system connected to the MEVI actuator rod. Instead he was using mechanical electrical device to engage the actuator rod. The device was hooked up to a MSD RPM switch. It was interesting so say the least. Him and Matt Blehm are working on making the setup a kit for sale to MEVI owners.

Nealoc187

iTrader: (23)

I thought of using an electromechanical solenoid to activate it too back when I was having harlan problems. Something like one of those automatic door opener/trunk popper things.

AsthmaMax11

iTrader: (3)

Well I put that new canister in today and wow. For the first time ever I have heard the MEVI open and Dave was exactly right about it sounding like VTEC.
I test drove a 2003 Acura CL-S 6-speed the other day and my MEVI sounds almost identical to the VTEC activating.
I suspect my old canister didn't have enough vacuum to fully open the actuator because ever since I put the new one in it sounds COMPLETELY different!