Problem with MEVI activation
11-01-2002, 01:03 PM
#1
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Problem with MEVI activation
ok...so my MEVI has been acting up lately, and it's REALLY wierd. My harlan works FLAWLESSLY. The red light ALWAYS goes at the set RPM.
If I set the harlan to 2000 rpms, and rev the car in neutral the light comes on and a split second later the VI actuates.
If I set the harlan to 5000 rpms, and rev the car in neutral the light comes on and then there is a nice hefty delay before the VI valves actually open, usually at about 5500 rpms if I'm revving slowly in neutral.
If I leave the harlan at 5000 rpms and take it for a spin. The VI doesn't actuate in ANY gear at WOT until about 6300rpms....same thing happens when I set the rpm switch to 4500 rpms....so I'm pretty darn sure it's not the rpm switch.
I don't have a vaccuum leak because when I remove the hose from the vaccuum canister that goes to the MAP switch...it makes a wooshing noise...so the canister IS storing vaccuum....anyone have any Idea why this is happening????
If I set the harlan to 2000 rpms, and rev the car in neutral the light comes on and a split second later the VI actuates.
If I set the harlan to 5000 rpms, and rev the car in neutral the light comes on and then there is a nice hefty delay before the VI valves actually open, usually at about 5500 rpms if I'm revving slowly in neutral.
If I leave the harlan at 5000 rpms and take it for a spin. The VI doesn't actuate in ANY gear at WOT until about 6300rpms....same thing happens when I set the rpm switch to 4500 rpms....so I'm pretty darn sure it's not the rpm switch.
I don't have a vaccuum leak because when I remove the hose from the vaccuum canister that goes to the MAP switch...it makes a wooshing noise...so the canister IS storing vaccuum....anyone have any Idea why this is happening????
11-01-2002, 01:29 PM
#2
Re: Problem with MEVI activation
So you're saying when set at higher rpms, the VI activates slower, especially when in gear?
Just verify that your canister is storing vacuum, and not just at idle. As you know, at higher rpm, the manifold vacuum drops so the vacuum canister storing function is critical here. It continues to STORE vacuum quite a few minutes after you turn the car off so you can test it by hooking up a guage in the line to the solenoid, and turning off the car. The vacuum level should be not change once the car is off for quite a few minutes. No guage? Check the canister for vacuum 10 minutes after the car has been turned off...
Edit: BTW, you do have a check valve in there before the canister right?
Just verify that your canister is storing vacuum, and not just at idle. As you know, at higher rpm, the manifold vacuum drops so the vacuum canister storing function is critical here. It continues to STORE vacuum quite a few minutes after you turn the car off so you can test it by hooking up a guage in the line to the solenoid, and turning off the car. The vacuum level should be not change once the car is off for quite a few minutes. No guage? Check the canister for vacuum 10 minutes after the car has been turned off...
Edit: BTW, you do have a check valve in there before the canister right?
11-01-2002, 01:38 PM
#3
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Re: Re: Problem with MEVI activation
Originally posted by Mishmosh
So you're saying when set at higher rpms, the VI activates slower, especially when in gear?
Just verify that your canister is storing vacuum, and not just at idle. As you know, at higher rpm, the manifold vacuum drops so the vacuum canister storing function is critical here. It continues to STORE vacuum quite a few minutes after you turn the car off so you can test it by hooking up a guage in the line to the solenoid, and turning off the car. The vacuum level should be not change once the car is off for quite a few minutes. No guage? Check the canister for vacuum 10 minutes after the car has been turned off...
Edit: BTW, you do have a check valve in there before the canister right?
So you're saying when set at higher rpms, the VI activates slower, especially when in gear?
Just verify that your canister is storing vacuum, and not just at idle. As you know, at higher rpm, the manifold vacuum drops so the vacuum canister storing function is critical here. It continues to STORE vacuum quite a few minutes after you turn the car off so you can test it by hooking up a guage in the line to the solenoid, and turning off the car. The vacuum level should be not change once the car is off for quite a few minutes. No guage? Check the canister for vacuum 10 minutes after the car has been turned off...
Edit: BTW, you do have a check valve in there before the canister right?
11-01-2002, 02:17 PM
#5
Maybe you just need a bigger canister. I'm not sure where, but when of these VI threads mentioned someone (speedtrip maybe?) having a giant canister from NAPA. Sorry for the vague memory. Hearing these vacuum issues about the VI makes me wonder if the VI plastic cover was shaped in such a way to also cover a big Nissan vacuum canister. There's a generous space under the cover. It doesn't show in any of the Nissan FSM diagrams. I wonder Where Nissan got the vacuum from 
Isn't it odd, though, that the only person on this board who has a Middle East Maxima which came with the VI stock is the dreaded ROADBEAST? I would hope that there'd be at least 2 or 3 people, either from Australia or Japan. Maybe even Korea.
DW
Isn't it odd, though, that the only person on this board who has a Middle East Maxima which came with the VI stock is the dreaded ROADBEAST? I would hope that there'd be at least 2 or 3 people, either from Australia or Japan. Maybe even Korea.
DW
11-01-2002, 02:40 PM
#6
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Originally posted by dwapenyi
Maybe you just need a bigger canister. I'm not sure where, but when of these VI threads mentioned someone (speedtrip maybe?) having a giant canister from NAPA.
Maybe you just need a bigger canister. I'm not sure where, but when of these VI threads mentioned someone (speedtrip maybe?) having a giant canister from NAPA.
http://forums.maxima.org/showthread....acuum+canister
SuDZ
11-01-2002, 03:20 PM
#7
Originally posted by dwapenyi
Sorry for the vague memory. Hearing these vacuum issues about the VI makes me wonder if the VI plastic cover was shaped in such a way to also cover a big Nissan vacuum canister. There's a generous space under the cover. It doesn't show in any of the Nissan FSM diagrams. I wonder Where Nissan got the vacuum from
DW
Sorry for the vague memory. Hearing these vacuum issues about the VI makes me wonder if the VI plastic cover was shaped in such a way to also cover a big Nissan vacuum canister. There's a generous space under the cover. It doesn't show in any of the Nissan FSM diagrams. I wonder Where Nissan got the vacuum from
DW
-hype
11-01-2002, 03:29 PM
#8
Originally posted by SuDZ
Took me a while but I found it, I think. Is this the one your talking about?
http://forums.maxima.org/showthread....acuum+canister
SuDZ
Took me a while but I found it, I think. Is this the one your talking about?
http://forums.maxima.org/showthread....acuum+canister
SuDZ
As for the under the cover canister placement, I would not recommend that. I have since moved it elsewhere because the area under the cover gets EXTREMELY hot (notice I didn't say warm).
As for the late activation delay only at higher rpm settings, I have no clue... The time delay after the set point should be the same no matter what the rpm. If the delay is prolonged but fixed, I would think that maybe the tubing from the solenoid to the VI actuator is too long or big, not enough vacuum, or the VI butterfly rod is hard to turn and takes time for the vacuum power to do it.
11-01-2002, 03:37 PM
#9
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Originally posted by Mishmosh
LOL. Nah, that is my thread. Speedtrip has a HUGE canister from Summit Racing.
LOL. Nah, that is my thread. Speedtrip has a HUGE canister from Summit Racing.
SuDZ
11-01-2002, 04:04 PM
#10
Originally posted by SuDZ
Oh I figured the part number you gave for the summit racing one in that thread might have been what they were looking for. Oh well.
SuDZ
Oh I figured the part number you gave for the summit racing one in that thread might have been what they were looking for. Oh well.
SuDZ
11-01-2002, 04:36 PM
#12
Funny, but that canister looks just like my hybrid intake
In fact, my hybrid intake was snuggled up to a battery post just like yours, and mine slowly frayed some bits off of my filter
I later installed the support bracket which I was too lazy to do in the 1st place. That held the filter just far enough away not to have it touching anything.
Anyhow, the reason I suggested a bigger canister is because, as mentioned before, the engine generates most of its vacuum at idle and less likely to do so at higher RPMs. So, if you're a rev happy, 4000 rpms and beyond kinda guy like I am, which I suspect that Briguy is as well, then maybe a bigger canister will have a bigger storage of vacuum to give until that time that Briguy finally reaches a stoplight
DW
In fact, my hybrid intake was snuggled up to a battery post just like yours, and mine slowly frayed some bits off of my filter I later installed the support bracket which I was too lazy to do in the 1st place. That held the filter just far enough away not to have it touching anything.Anyhow, the reason I suggested a bigger canister is because, as mentioned before, the engine generates most of its vacuum at idle and less likely to do so at higher RPMs. So, if you're a rev happy, 4000 rpms and beyond kinda guy like I am, which I suspect that Briguy is as well, then maybe a bigger canister will have a bigger storage of vacuum to give until that time that Briguy finally reaches a stoplight
DW
Originally posted by xHypex
The vacuum canister really doesn't have to be too big. My canister came off a 3rd gen which also has a VI. My Harlans have always worked correctly, and my VI has never failed to open.
-hype
The vacuum canister really doesn't have to be too big. My canister came off a 3rd gen which also has a VI. My Harlans have always worked correctly, and my VI has never failed to open.
-hype
11-01-2002, 04:49 PM
#13
Originally posted by dwapenyi
Anyhow, the reason I suggested a bigger canister is because, as mentioned before, the engine generates most of its vacuum at idle and less likely to do so at higher RPMs. So, if you're a rev happy, 4000 rpms and beyond kinda guy like I am, which I suspect that Briguy is as well, then maybe a bigger canister will have a bigger storage of vacuum to give until that time that Briguy finally reaches a stoplight
DW
Anyhow, the reason I suggested a bigger canister is because, as mentioned before, the engine generates most of its vacuum at idle and less likely to do so at higher RPMs. So, if you're a rev happy, 4000 rpms and beyond kinda guy like I am, which I suspect that Briguy is as well, then maybe a bigger canister will have a bigger storage of vacuum to give until that time that Briguy finally reaches a stoplight
DW
11-01-2002, 04:52 PM
#14
Engines make it's highest vacuum at idle.
Originally posted by Mishmosh
Even a modest canister has enough storage to activate the actuator a few times without any vacuum replenishment. Besides, the greatest vacuum occurs at high rpms with the throttle plate closed, ie. letting off the gas at high rpm.
Even a modest canister has enough storage to activate the actuator a few times without any vacuum replenishment. Besides, the greatest vacuum occurs at high rpms with the throttle plate closed, ie. letting off the gas at high rpm.
11-01-2002, 10:54 PM
#15
Originally posted by dwapenyi
So, if you're a rev happy, 4000 rpms and beyond kinda guy like I am, which I suspect that Briguy is as well, then maybe a bigger canister will have a bigger storage of vacuum to give until that time that Briguy finally reaches a stoplight
So, if you're a rev happy, 4000 rpms and beyond kinda guy like I am, which I suspect that Briguy is as well, then maybe a bigger canister will have a bigger storage of vacuum to give until that time that Briguy finally reaches a stoplight
-hype
11-02-2002, 06:55 AM
#16
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When bags533 was having problems with his VIM activating he traced it back to the actuator arm which was slightly bent.
One thing I have noticed on my maxima is that when I am testing the VI at 2k rpms it activates when the tach displays 2k rpms. When I have the rpm switch set 5000 rpms the tach is reading 5200 when I hear it click. My switchover is not delayed as you are expeiencing but my dynoes have cleary shown that the switchover is occouring at 5k rpms. So don't forget there's a little error in the tachometer.
One thing I have noticed on my maxima is that when I am testing the VI at 2k rpms it activates when the tach displays 2k rpms. When I have the rpm switch set 5000 rpms the tach is reading 5200 when I hear it click. My switchover is not delayed as you are expeiencing but my dynoes have cleary shown that the switchover is occouring at 5k rpms. So don't forget there's a little error in the tachometer.
11-02-2002, 08:26 AM
#17
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Originally posted by speedtrip
When bags533 was having problems with his VIM activating he traced it back to the actuator arm which was slightly bent.
One thing I have noticed on my maxima is that when I am testing the VI at 2k rpms it activates when the tach displays 2k rpms. When I have the rpm switch set 5000 rpms the tach is reading 5200 when I hear it click. My switchover is not delayed as you are expeiencing but my dynoes have cleary shown that the switchover is occouring at 5k rpms. So don't forget there's a little error in the tachometer.
When bags533 was having problems with his VIM activating he traced it back to the actuator arm which was slightly bent.
One thing I have noticed on my maxima is that when I am testing the VI at 2k rpms it activates when the tach displays 2k rpms. When I have the rpm switch set 5000 rpms the tach is reading 5200 when I hear it click. My switchover is not delayed as you are expeiencing but my dynoes have cleary shown that the switchover is occouring at 5k rpms. So don't forget there's a little error in the tachometer.
I'm suspecting my vaccuum canister now...I'll have to make sure it's not leaking vaccuum. That still doesn't explain why it would switchover at 6400 if it didn't switchover earlier....I'm so confused...
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