I know guys often say "yeah that run was with butterflies stuck open", etc. How did they get "stuck"? I changed injectors and they are fine, i'm getting tuned tomorrow as well. I slapped on the 2.87" pulley, Z32 injectors, and when I put it all back together, no CEL, idle is fine, car is a little sluggish though, I guess i'm running very rich, always have been, but now def am. So I am taking it to get tuned tomorrow. But I rev the car up using the throttle cable in the bay to when my butterflies open (5k), (I took it up higher, I can just tell) and the little actuator didn't activate. So I rev up inside and check my switch and the LED lights up at 5k telling me the switch is diong it's job and still working. Should I cancel my tuning/dyno appointment tomorrow until I get my MEVI situation sorted out? What could be the issue though? I'm pissed right now. I really need tuning, car feels like crap.

 

just do a dyno run with it as it is---closed and tune under 5K...then zip tie or hold it up when you dyno...and proceed to tune above 5K...meaning you tune below 5K until you get as much power added as the dyno operator thinks is possible, then do the same thing for the upper range--above 5K with the mevi tip tied open...it will take some more time/extra runs but you can still get it done...

the led on your rpm switch is simply telling you it is sending the signal to the selonoid...but it doesn't mean your selonoid is working or your vacuum canister is sealed well and keeping vacuum...

 

Good effing idea, lol. Anyone object, I think this will work. For tuning this will be great, as far as power, I won't know what I can really do, i'd have to like combine the bottom end of the stuck closed runs with the top end from the stuck open ones.

 

something like this happened with mine. The mevi would work when in idle but when on the dyno or driving it, it didn't open. The led still came on when the car was at 5k but it was not working. It turned out that the check valve for the vac canister was broken so i just got another one from pep boys and put it in. I found the one way check valve in the help section or something it was a couple dollars. Try that first and see what happens. You could also check the other vac lines and the wiring for the soleniod.

 

The check valve? Mevi, has the golden/brass actuator thingy, then you have a vac line to the canister, then the other vac line from the canister goes to the switch. Where is the check valve? AM I calling something wrong? You think they might have it at autozone? Thanks!

 

It's most likely just a vacuum problem. A way to check is to remove the line running from your vacuum source to the canister after the car is turned off. If when removing that line there is not a rush of vaccum from the canister then your canister is not holding vacuum. Just put a check vale in line between your vacuum source and the canister.

 

Sounds like a vacuum too, my vacuum canister was cracked which I found out on the dyno. I did a pull with it shut and one with it open so I can play with the switchover rpm. Are you using a summit switch and a ac delco vacuum switch? Even tho you led is lighting up, make sure the other they are making a good connection.

 

Sounds like your cannister has an interanal Check valve.
Try the external one, it will go in between the cannister and MEVI.
If that doesnt fix it, the VSS may be bad. I had the same problem a while back.

 

Thanks fellas. I went to autozone for the one way vacuum check valve. Of course they don't have it. So I guess i'll be ordering it online. I rescheduled for a Tuesday dyno tune session so I should be set. .

Thanks everyone, and abci30 for IMing me and helping me find the part.

This is the piece I had overnighted:

Check Valve

 

I did it a really ghetto way one time. I only noticed they didn't open while it was on the dyno. We just tied electrical wire onto the actuator and pulled it open at about 4500 rpm. You're probably only interested in peak HP anyway so pulling it at 4500 rpm will let you see that. Although, if you know it now, I would fix it first.

 

LOL, that's hilarious. Very creative. The vacuum check valve was delivered this morning, so tonight i'm gonna insert it and pray that was the problem. Then I can finally get the car tuned.

 

Well guys!!! The shyt didn't work. I put the check valve between the vacuum source and the middle stem of the vacuum canister. The rpm switch works. It lights up when I start the car to let me know it''s working. It also lights up at 5k the way it's supposed to. Butterflies still don't open up. The system is, vacuum source (coming from behind the intake manifold) to the center of the vacuum canister. Then vacuum line from the other stem of the vacuum canister to the rpm switch thingy, then vacuum line to the actuator that's supposed to flip open the butterflies. Maybe I should just bypass the switch and run a vacuum line from the source straight to the actuator on the mevi to test if it's a vacuum issue???

Would I get more help in the all motor forum or 4th gen forum? Mods please move to where you think i'd get more help. I don't think this is a "boosted car" issue anymore. Thanks.

 

Sounds like your VSS may be bad.

 

may need a new solenoid

 

VSS means? Thats the brass actuator that opens and closes the butterflies right? If so....link to a new one please. Thanks. I'd like to throw this on so I can dyno hassle free.

 

VSS= Vaccum Solenoid Switch


Pic posted by zack342

 

If I hook the actuator up directly to the vac source, and it opens, I will know for sure I need a VSS. Link to where I can get a good one? I just used and didn't get any good links to purchase one. Thanks.

 

i got that one from a VQ30DE in the junkyard. its an OEM nissan one. check your local junkyards.

 

Where the hell is that located on the motor? My friend has a parts car, maybe I can pull it off. If not, i'd go OEM if I can. But they sell an aftermarket VSS somewhere because the one I got isn't OEM.

 

That summit switch looks like it has NOTHING to do with letting vacuum pass through it at a certain RPM. WTF.

 

Lots of vehicles use them, but honestly I wouldnt go with a used one again.


I bought this one,..

GM PART # 1997152
http://www.gmpartsdirect.com/results.cfm

 

I will take pics of where i got it and how i installed mine. the reason i say getting that one is because they are quite robus. I mean nissan uses then on the motor and i don't recall every hearing anyone having to replace one. Many people have 100-200k on their motors. plus it looks stock i don't like the way the GM solenoid looks. it looks lost in my nissan engine bay.

 

That one posted earlier looks just like the one I had that went out,



The GM one that I have now doesnt look too much different, I'll try and get a pic of it later on.

 

 

Thanks a lot guys. I just blindly went and ordered the GM solenoid for now.

 

This came in today. One prong is power the other is ground? I has a female connector on it with 2 prongs. One vacuum hole is covered and 2 are exposed. How did you install this in your system? I have a Harlan RPM switch I believe.