95-99 VAFC II Writeup Complete.
 

Just finished with the writeup for installing the VAFCII into a 4th gen with 00VI/MEVI. Writeup is useable if you have standard USIM, just scratch the VIAS wire.

http://www.vqpower.com/v2/readarticle.php?article_id=98

:doublethu

does your thing show Throttle percentage? mine dont work

Just out of curiousity...why is it that is was said you have to position the sensor numbers to 1 in 1 out? Thats the way I have it and ther hasnt been any problems.
I, unfortunatley, dont have the VAFC II manual so I cant research the numbers, but is there anywhere else I can look at to get an idea for myself why it needs to be at those numbers?? I've tried looking into the Apexi website for information on the VQ35's but I guess i'm not looking in the right place.

Also why the knock sensor inputted to the vtec in?

Yes, you would have to go to the 4channel Monitor to show TPS %

Well, in the VAFC Installation Manual there is no specification on what exactly these numbers are used for let alone their different functions. I would need to search again for more specific functions for the IN,OUT sensor instructions. I havent had a problem so far with 4IN,4OUT just yet with stock MAF and DEK injectors.

Sorry that was supposed to be cut out

Actually, you can even show it on the 2 and 3 channel monitoring if you want, you just have to select what to display. I have mine set to display MAF, Throttle %, and RPMs.

Good work Luke.

Nice! Thanks for taking the time to do this. :clap:

I just wanted to confirm, no adjustments or settings need to be changed when using a Z32 MAF, right?

I believe someone stated that the Sensor NO's need to be slightly adjusted to correspond with the Z32 MAF. If you do a quick search I believe it is in a recent thread.

:cool:



.

thanks mayne! (in for waiting for explaination of the IN/ OUT sensors)

Unless you have a different/altered MAF &/or MAF housing, you leave them the same. 4/4 seems to work as well as 1/1, who knows, any like # (2/2, 3/3, 5/5, etc :russ: ) may also suffice.

Great work as usual :ben::ben:

Do you know what the settings should be for a A32 ECU with a Z32 MAF? Yes, I did RTFM. All they say is to "set the sensor based on your vehicle". Gee thanks, that's pretty damn vague. I think they forgot a chart or something. Maybe I just don't get it, or the VAFC instructions are different than the SAFC instructions in this aspect. Please shed some light on this topic if you know. Thanks. In the meantime, I'll be :reading:

This thread gives a little insight into what I think the Sensor NO. should be set to. I will be looking into the SAFC manual later today to see if that manual has any specific MAF #'s.

Thread:
http://forums.maxima.org/showthread....highlight=vafc

The 2in 2 out doesnt work. I tried it and the car shuts off.

Little insight is correct. I'm still confused. I'm thinking the SAFC manual has specific MAF numbers, where the VAFC does not.... time to download the SAFC and check it out.

This is the only thread that comes up with a quick search....
http://forums.maxima.org/showthread....t=VAFC+Z32+MAF

However, there's no happy ending. :banghead:

Ninja edit: I think I figured it out....

I dowloaded the SAFC and SAFC-II instructions.

Looking at page 2 of the SAFC (not SAFC-II) instructions, our good ol' Maxima is listed... as HW-4. The 300zx is listed as HW-2

Now looking at page 45 of the SAFC-II instructions, they give an example of the "in" and "out" and use a Z32 MAF on a SR20DET and show that the 'in' is set to 2 and the 'out' is set to 5. (Normally, it would be 5 in and 5 out if the SR20DET wasn't modified)

So, by putting the pieces together, it appears that the correct setting is:
in 2, out 4 This applies to the A32 maxima only using a Z32 MAF.

If the A32 MAF is used with the A32 ECU, then the settings should be: 4 in, 4 out


Please correct me if I'm wrong. Thanks.

Great, I will be updating the writeup with this information!

I just checked and it appears I've been running 6/6 for almost a year....meh, maybe I try changing it to 4/4 and see if anything changes... or if a retune will be needed.

Why change it if it's doing fine :gotme: No reason to unless your AFR is severely off. And the only way that would occur is if you change the housing &/or sensor.

I suppose.......

Sounds to me like the in/out settings are related to global scaling. If you have the stock MAF, any setting would work as long as they're the same number for in and out, which would mean no scaling is applied. If you have different in/out then maybe a global scaling is applied...

This is just a speculation based on what I've read in this thread, not from actually reading the manual or anything. Someone can confirm whether that's correct I'm sure...

I just finished thoroughly (sp?) reading your writeup. The only item of confusion I could forsee someone having is the Blue (O2 sensor wire). The VAFC-II instructions show cutting the appropriate wire, and joining the blue wire to end going to the ECU. The other end remains taped off. Your instructions don't state whether to cut and join (like the VAFCII instructions), or tap the appropriate wire. I believe tapping the appropriate wire is implied, but not directly IMO.

Overall, very good writeup. Thanks again for your efforts.:doublethu

Well, being as the O2 Sensor wire is not really necessary I was quite vague about it. I do see how that could become a problem if someone was to try and tap the O2 sensor so I will make note of the proper installation procedure. Glad you all like the writeup, I plan to make more when interesting projects come up(frequent occurence down here).

thanks for helping the VI/V-AFC2 community! I've done mine last weekend and I'M currently looking to get it to activate.

All you need to do to get it to activate,

Settings; V/T Cont.; Now what needs to be done here is set L->H and H->L switchover points.

EX:
L->H: 5100
H->L:5000

good writeup.

i've had my vafc2 installed for a while now, but i haven't cut the MAF wire yet, which i will do when i have time to tune. right now it's just acting as an rpm switch.

any suggestions on how to tune? i'm not even sure where to start, i think we want to use all 24 points spread out across the 3k-redline rpm range, correct?

You can intercept the MAF signal even if you arent ready to tune, i have been driving this way for almost 3k miles now and not a problem yet. Yes, you will need to adjust the 24 points into the 3k+ range, I tried twice to dial it in in 200rpm increments and also 300 rpm increments and I finally ended up spacing it on in 300 RPM increments and then 200 rpm increments for a couple areas. IE.

LV:
3000
3100
3300
3500
3700
3900
4100
4200
4400
4600
4800
5000

HV
5100
5200
5300
5500
5700
5800
5900
6100
6200
6300
6400
6500

It's finally alive and well. It works but dont forget to get the vacuum for the VI switch before the tb!! last thing I needed to get it to work properly.
I remarked something by the way. When my car shifts (yes its automatic)
back to 4200 in third, the ecu seems to have a hard time to get the correct amount of fuel to inject, it feels like a dead spot in the fuel map. It still accelerates because of the tranny slipping/getting to gear, but It seems a wait in ecu calculation or something else. Maybe a good dyno run would help to figure the good a/f ratio. not really a concern because the car is riding well but only a remark. If something comparable happens to you, let me know. I dont want to blind-tune my V-afc because of that.

somebody wrote about -3%/-4% from 4000 to 5000 and -6% up to redline but actually, doesn't feel that much better. Maybe the proof that each car performs differently from another. next step: zeitronix zt-2 may be something that would guide be better to tune it myself

Why would you go off of what someone said, actions like that is what blow motors.

dude, you dont even TOUCH that AFC until you have a way to look at the a/f ratio. If you dont know how rich/lean you are, why the heck would you start doing correction? thats just beggin to blow your motor. Get a wideband or go on a dyno with a sniffer , THEN do corrections :slap:

+1. that's why mine is just an rpm switch for the 00vi right now. i'll tap the MAF wire when i'm ready to dyno tune.

You can tap into the MAF wires, just dont make any corrections.

This seems like the go-to thread for V-AFC II info, so I figured I would ask in here. It is said that the VAFC2 has a knock sensor monitoring function, and obviously connects to the knock sensor wire, however I can't find anything related to the knock sensor in any of the menus or owners manual. Can anyone shed some light on this? It would be nice to be able to monitor knock.

The value is a unit less number, as so, it essentially means nothing. IMO.

Check the FSM wiring diagram (I know pmohr has it in one of the stickies). Locate the KS wire & tap it in.

But, IMO, it is not worth the hassle.

I already tapped the wire when I did my initial install. From the looks of it, they mention knock sensor monitoring in the manual multiple times for the SAFC-2 but not the VAFC-2.


Perhaps features were sacrificed in the VAFC-2 to make room for the added correction points and vtec control features?

If so, why would they provide a wire for it?

does any one else have a japanese VAFCII? Manual, fold outs, warrany card all in japanese only???

I don't think so. My VAFC2 is in english, it didn't come with a manual or warranty card though.


BTW I think I figured out the whole knock sensor issue. I must have been looking at the SAFC2's wiring diagram where the purple wire is for the knock sensor. Apparently, the VAFC2's purple wire deals with vtec control.