Well to my suprise, after doing my motor, my mevi is not opening under WOT. Perhaps its wasnt opening even before i did my motor, im not sure, cant remember.

Im at my wits end with this, im seriously about to get rid of it, because ive had nothing but bad luck with it. I honestly dont know what im doing wrong. I can verify its not opening, if i watch my airflow % on my safc2, when it doesnt open the airflow % drops to about 47% at 6000RPM, whereas when i tie it open manually it just keeps rising till 6500, where its at about 56%. If i rev it with no load, the mevi opens, at 5200rpm. Now, in gear it does not open, first, second, third..etc no luck.

Now ill try explain this my best, the setup i have. All the wiring for the control solenoid has been re-done, all proper wire, properly crimped and all.

I have a summit RPM switc, REMY Control solenoid (GM), Nissan OEM Vac canister, with built in check valve. I have a spare nissan check valve that ive also thrown into the mix to see if it helps to no avail.

Electrical side:

RPM Switch. Its on ignition power. The yellow "activation" wire is going to the ground of the control solenoid. The Red, goes to ignition power, white is tach signal..im using the rpm signal from the ECU. Black is grounded to the chassis.

Control Solenoid: Its getting the power from the same source as the RPM switch, i tapped ignition power from the fuse box right near the battery. The ground again is connected to the activation wire on the RPM switch.

Vacuum Side:

Vacuum Canister: Vacuum canister is getting its vacuum from the fuel pressure regulator, i have a T fitting, that goes from the FPR to the white port on the vacuum canister. The other port, goes to the Control solenoid, the side that has the crimp thing on it.

Control solenoid: There is 3 ports, to my knowledge/testing, the single port is a breather, the other two are used for releasing the vacuum stored in the vacuum canister.

I am almost 100% sure this is hooked up correctly, ive tried switching around the vacuum lines, and the mevi doesnt open at all. More specifically if i swap the lines on the vac canister, nothing happens, but if i swap the lines on the control solenoid, the mevi opens at 5200, but stays open, and slowly closes, but re-opens at 5200. Again it does not open under load.


Here is the only thing. When i received my mevi, i guess during shipping, ups damaged it, the nipple, on the actuator got cracked, i did not realize this, i JB Welded it, and ive tested it several times, used a hand operated vacuum pump, pumped it up to 30mmhg and it does not loose the vacuum, so its fine.


If anyone can help me, i honestly dont know what else to do. I dont want to start throwing parts at it, becuase right now i have more important things to be saving my money for. I dont know if this may be a common problem or not. But how many of you are 100% sure your MEVI is staying open during shifts?

Thanks again guys!!!

 

man, i remember when u had ur problem a few months back, i thought u had it all straight after then. that sucks. anyways, maybe check all of your hoses and make sure they're tight, i remember t6378tp had a problem and it ended up being that he needed to tighten a hose or two. ill have to check my setup and let u know what it looks like. im 100% positive mine opens up because ive seen it on a dyno and i took ot for a spin without my hood one day cuz while it was being worked on.

 

That is your problem.....I remember people having problem with teeing off the FPR under load......IIRC the vacuum goes down at WOT.....

Try putting your vacuum line to the canister directly from a straight line like off the intake or if you still have your vacuum tree try and see if there is an open line or tee directly off that.....


That hopefully will fix it.

 

Ahh alright. Perhaps thats why i had teed off the intake manifold previously. I couldnt figure out why i had teed off the manifold versus the FPR seeing as how much closer it was.

I spent another hour or so re-trying things, i re-grounded the rpm switch, its grounded to the chasiss, right now, its hard to tell in first gear, but according to my safc2 it is opening in first gear, but second gear it doesnt open, even if i slowly bring it up to 5500rpm, then slow down to 4800, then put my foot to the floor.

Ill try re-teeing it off something else.

Im contemplating on trying a different rpm switch, because after reading for another 45 minutes of old threads that bruce made, i think it could possibly be that. Theres nothing else i havent replaced, the control solenoid is from the previous owner, but i really do not think thats the problem, because it does open and close.

It sucks, because i was going to start installing the turbo, but i think i should get the car 100% running before i do anything else. Just welded on my new bov flange onto my intercooler piping, so its ready to go

 

Do you have a summit switch?

 

i have heard the people say the same things regarding the frp as a vacuum source but i havent ever had a problem with using mine as one. i dont understand why this happens to u, we have the same setup of parts minus the canister(mine is from NAPA, but even my big balloon looking one worked before)

 

The same happens in the intake manifold, since that's where everything gets its vacuum from..

 

I had the same problem and it was a loose hose, it was fixed by putting a clamp on it

My mevi would open then slowly close cause at idle and low rpm the engine is making more then enough vac to over come the leak and still open the mevi but at wot there is very little and if everything is not sealed the mevi will not open or will open and slowly close

if that is all good check your electrical connections maybe one of them is loose and is intermitten

 

Yeah i have a Summit switch. Tomorrow hopefully the weather is a little better, im going to try a different vacuum source. Ill double check the electrical connections, but as of now, if a different vacuum source doesnt work, im leaning towards the rpm switch.

 

bad vac canister (or bad check valve). i had this problem back in the day.

when you test the MEVI in your driveway, revving the car up, you still have vacuum in the intake manifold, which causes the MEVI to get sucked open like it should. when you are driving the car and you go WOT, you have no vacuum in the intake manifold, and because your vacuum canister or check valve is bad, you have no vacuum stored up waiting to suck the MEVI open (that's the whole point of the vacuum canister, to "store" vacuum so that you can suck the MEVI open even when there is no vacuum in your intake manifold).

 

Well put a check valve in, still not working. rewired everything, tried teeing off the manifold, still nothing. I think the only thing left is the RPM switch.

anyone have a summit rpm switch forsale?

 

I know I'm going to get a lot of flack for saying this, but maybe consider going with a Harlan RPM switch this time around.

FWIW, I've installed several MEVI's, all with Harlan RPM's, and years later, not a single problem. I know others have had problems with the Harlan and absolutely hate it, but not me.

 

blasphemy!

 

LOL it was a good idea but if you hooked it up wrong, the game was over. Summit is a better choice now a days.

I thought I was having the same issues when I installed my MEVI (which I used to call mine "JPVI" because mine came staight from Japan) but after testing it on the highway on one of my commutes to work, I actually felt the extra power while accelerating up hill. I can't prove that it worked 100% of the time but it seemed to have worked flawlessly up until I got rid of it earlier this year.

 

I'm sure you covered this already but did you check to see if your RPM switch is activating? Do you have it wired to your cigarette lighter switch?

Just a noob question since my cig lighter fuse blew when I first started up my car.... Just a thought because my VI stayed closed when, then when I changed the vac lines around it stayed open and flutctuated a little w/ throttle applied.

 

lol...i was never able to get my harlan to work right. Now I use a VAFC2 and no problems. Im not sure how the summit wires up so I cant comment on the op's setup but you could check if its bad by contacting the solenoid to ground while you push the throttle body back. That way you know its a wiring/switch problem as opposed to vacuum.