I have Z33 injectors (DEK) and they bolt(more like snap) right in. Only thing is that the trip computer (not that it ever was accurate before) reads betwen 27-31 MPG on highway trips.



At this point, I think fuel starvation is the last of your worries.

 

yeah i realize it would have to be turned down as far as possible

 

when did you get Z33 injectors?

 

It's been months.

 

so if I have the 5th gen injectors and a VAFC2, I just got my WB, can I take out fuel and it will adjust the timming?

 

5th gen injectors are already bigger so taking out fuel may do the trick alone. But its always a good idea to have an AFPR wanyhow.

 

how do I take out fuel with the VAFC2? or add?

 

By using the correction factors. Negative #'s take away fuel, positive #'s add fuel.

 

how do I know if the VAFC2 is adding or subtracting fuel?(by rechecking the AFR) BUT which wire is it that needs to be connected to the ECM that makes these changes on the VAFC2 possible? I wired mine up according to this http://jime.homeip.net/S-AFCII4thGen.html

 

im not going to give you a crash course, sorry. if you cant figure it out dont touch it and have someone else set it up. its very hard to learn without doing it.

 

im not asking for a crash course, i have everything set up already.... all im asking is which wire is it that when you adjust the correction factors, the correction factors will work because of that special wire, which is that special wire? is it the MAF wire? does the correction factors change the MAF voltage which in turn tell the ECU to send in more/less fuel because there is more air? or something like that?

 

Yes ^^

 

is that a yes to all of my questions?

 

listen I found out some useful info. every 5 points is -/+1 deg.

goldtooth research the old threads its has been answered.you dont even got to use search funtion.

 

Supporting info please

 

when I was at school with there universal scanner I noticed at idle every five points would add or subtract 1 degree in advance.so I did a couple of thrid gear runs. and found out this is tru.But Im gonna be getting a second opinion from a diff scanner so I can get pictures and what not.

 

actually ether are 2 wires...they are ones that u actually have to cut to interrupt the MAF voltages and connect to the VAFC....on a stock ECU u run rich ....so the AFC will change the MAF voltage to thinkning there is less air comming in so the ECU will send less fuel essentally leaning it out.........previous questions about fuel pumps....the fuel pump is always running at full pressure so longevity of the fuel pump when turning up fuel pressure is not an issue since fuel pressure is regulated by the regulator and not the pump....as long as the injectors arn being pushed to 100% of their duty cycle they will be fine...and u have to remember for the most part atleast in 4th gens I think the corrections will only come into effect above 40% throttle and above 3k rpms..so its not a constant pounding.....and please get it tuned by someone who knows what they are doing....at minimun with an 02 tail pipe sniffer...preferably an wide band

 

hmmm not sure if I'm reading your wording wrong or what, adding or subtracting shouldn't make any changes to timing advance at idle.
Interested to see your final results though, please keep us updated.

 

how does that work per rpm/ throughout the entire rpm band? wouldn't it differ at various rpms unless its tuned?

 

I will keep yall updated Im waiting for a program to come in the mail,so i can datalog on my laptop and show pictures.As for the idle If you unplug the tps sensor it runs 100% there for I think I was able to advance timing.But I see what exactly is going on when I get the software

 

Details please.

 

http://www.autoenginuity.com/products.html


it comes with a a performance program that im not sure will work but its free so worth a try.

 

SR20DEN give me a shout via e-mail rthorne5@gmail.com
i want to run some ideas by u. i doing a swap from a VQ2.0 TO 3.5.

 

http://forums.maxima.org/showpost.ph...78&postcount=8

 

ok guys, I have tuned with the WB and VAFC2. My mods are 00VI, Budget ypipe, and test pipe(with WB installed in there). I street tuned in 2nd gear (AUTO) to an AFR of 13.0- 13.5. How does that look, is that a good AFR for my mods? and what can I use/ buy to check my what my timming advance is, cuz Im curious...?
Thanks

and on the VAFC2, there is this thing that u set the throttle percentages to: I have it set to 40% and 90%, is the 40% when its open-loop? what is the 90% for?

 

Auterra can tell you your timing.

 

If I understand it correctly under 40% is closed loop, 40-90 is partial throttle and over 90% will be open loop. So your AFC won't make any changes until you go over 90% throttle and 3k RPM. I've seen most people here set it at 39-40%. Think I set mine at 50-70, seemed to smooth out my acceleration with a higher % up top.
We might need someone to shed better light on this also.

 

http://forums.maxima.org/showpost.ph...4&postcount=14

 

well i had mine set to 39-40% yesterday, and when I go over 40% and over 3k, it starts correcting already (for example my first correction at 3k -13) and the car just bogs, this is because since im not at WOT, there is still vacuum on the fuel pressure regulator, which means that -13 is leaning out the mixture too much since its not at WOT fuel pressure. soooo, i followed what SR20DEN said back in 05 on this same thread, page 2 i think, he said he put his at 15% 85%.. at 15% the narrow map is used, at 85% the wide map is used. now, if your below 85% but above 15% after 3k, then it gets the middle point between the correction at 3k of the narrow and the correction of 3k on the wide. in my case, I have all narrow corrections at 0, and wide starts at -13. so between 15 and 85, it corrects like half about -6 or so depending on throttle position. makes it alot smoother. I think i have mine now at 10% 90% actually. i just changed it today. feels nice and smooth.

with that said, look at page 40. http://www.apexi-usa.com/pdfInstallation/25.pdf

 

Hey yall, I have adjusted my fuel pressure to 45psi at idle, goes to bout 54psi at WOT. I tuned to bout low 13's, the car feels like iv never felt before, pulls very hard. Any predictions on how much I could have advanced timing using the stock injectors, walbro 190. Or to many factors to really know?

 

Do you have a auterra handy or something to monitor your timing. That could be used to see how much timing was advanced. But other than that you may have to dyno and I don't know if you had a base line to begin with.

 

nah i dont have anything to check timing, and how would a dyno tell me? by giving more hp it would tell me i advanced?

 

are u sure...I have my low throttle at 39 and hi at 40 and only tuning hi-throttle past 3k Rpms

 

I suggest you read my previous. because what if your over 40% throttle but below 100% throttle, your hi-throttle is going to be tuning using the corrections you have at that wide hi map, which is not good because ur fuel pressure is not going to be at WOT fuel pressure, so those corrections u have, are going to lean you out too much and in my case i even felt the car bog a bit when i was over 3k and not at WOT. Try putting it at 10% 90%, you will feel it alot more smoother because it will calculate a certain correction when your not at WOT but above 10% and above 3k.

 

FYI- 3.5 owners and 3.5 swappers, obvisouly the vaccum to the FPR issue does not apply to us since we run once constant pressure with no vaccum (3.5 bar).

However, I can vouch for what the man is saying. I too had my TH-Point set to 39%-40%, and its now at 15%-85%, and my dip in power at 3k doesnt feel as bad during partial throttle. I dont have a WBo2, so I cant provide any other data other than butt-dyno feeling smoother FTW

Doing this wont show any gains on the dyno, because at 100% throttle the AFC uses its wide corrections, which stays constant in this. What it does is smooth out the a/f when you are in open-loop already but NOT at 100% throttle. For example spirited acceleration (none-racing-style) in the street, you might hit 50% throttle--> this is when that change in the TH-point takes place. If its set at 39-40, then you will have the FULL correction of A/F, even if you're not at 100% throttle. With the TH-Point spread like streetz is saying, the AFC will interpulate the correction according to the throttle input % UNTIL you go passed say 90% throttle or w/e you set the highest # to.

Hope that helps to understand the theory behind this.

 

What I'm saying is if you did a base line dyno before you changed your setup. So that you can see if the new results are higher than before. This will give you an idea if timing was advanced.

 

This is from Streetz under my s/n cus he forgot to sign out like a n00b

oh yea thats true. well from a butt dyno point of view, and from a few quick runs vs. buddies 3.5swap and mustang GT, i DEFENTLY gained something but i get wat ur saying, im going to actually use a scanner soon hopefully to check timing.

 

Hey Streetz. Changing my setup to 10% 90% really helped out. Before the car was losing power and than it would kick in like boost. Now it just continues to make power b/c the VAFC-II is interpolating the points when I spirite drive.

 

thank streetz but more importantly SR20DEN, he's the one that "learned" us about this setup.

So from us to matt, thank j00! lol

 

your welcome =), but yea I read an old post on this same thread on page 2 about SR20DEN setting the throttle %'s like that. Then i went to page 40 on the VAFC2 manual and finally understood what they were saying lol. So iv just been showing people how it works and so far everyone is happy including myself. so yea. thanx SR20DEN for learning us lol.