Hey guys, hoping for a little incite here on something. When I got my most recent mods done, I put in 350z injectors. When I went to get my APEXi Neo tuned, the guy said that it was running about 8% richer. When he tuned for hi throttle, it pulls anywhere from 5-10% depending on the RPM.

My problem is that I have been getting terrible gas mileage, even on the highway. I only get about 21mpg, and I know the tune has something to do with it. He has low throttle set to "+5" all the way across the RPM band. So to me, that says if it was running about 8% rich before, it's now running about 13% rich in low throttle (he has it setup from 10%-49% is low throttle and 50%+ as high throttle). I figure I have to be able to adjust that down a good bit so that it's not running as rich and I get better all around mileage.

Before I get 7 replies saying "BUY A WIDEBAND!!" I am going to, I just haven't yet. All I want to do in the mean time is get the car within a normal range, nothing perfect, just better than what it is now. I set the NEO to be +3 all across the board at low throttle, but I think I could safely tell it to pull fuel at low throttle.

I just wanted to see what people had to say about this. I think the tune on here left alot to be desired, especially because I know at the end, he just set all of low throttle to +5 and didn't even dyno it after that. If the settings for high and low throttle good? (10% and 50%) Thanks everyone, I look forward to fine tuning it once I get my wideband.

 

1.) Why did you let someone condition your AFR that doesn't know much about VQ Maximas?

2.) What did he 'tune' to (AFR)?

3.) I do not see any reason to tune low throttle unless it's a special case and you have a WB.

4.) Go back in there (Settings) and remove the +5 and set it back to '0%' for Lo throttle.

5.) Don't play with any other settings unless you have a WB, or are going back to '0'.

 

No good places just for Nissans around here and he said he could do it.

Between a 12.5 and 12.8.

Well its more for fuel economy so when you're not on it you can lean it out a little.

Ok I was just working in small steps before getting down to 0 since I don't have a wideband.

I won't mess with anything else but do you think that I will be able to pull a good amount or fuel out for low throttle when I get a wideband? I still think at 0 its running rich but have no way to actually prove that at the moment.

Thanks fot answering my questions!!

 

Any reason why you went w/ Z33 injectors, is this for the TA?


The ECU does a fair job doing it on its own when cruising, it's WOT where it has some trouble.

With the knowledge & information on here, I think you would be a better tuner.

Going back to 0, theoretically puts back in the same position as it was before it was installed.

 

For the TA??

And I have it at 0, calibrated the throttle since it was never done and the car feels like it runs alot better and my DTE went from 287 on a full tank to 350!! Sweet!! Thanks!

 

TA = timing adjustment? Presumably so...

 

Timing advance, yes.

How long have your Z33 injectors been in there?

Reason I ask this because when you add larger injectors, when in closed loop, the ECU needs to compensate a tad more, and so the DTE/MPG goes up a bit, I noticed this also when installing Z33 injectors.

So with that said, if you hadn't traveled very far since the install of the new injectors, it would make sense that's what was happening. But, just because it goes higher, doesn't mean you're getting better MPG.

And again, didn't even think of it until now, but why would he add @ low throttle, it makes it even worse w/Z33 injectors.