Thread: Why won't my AFR's decrease???!!!

Here's the story:

92 SE-R, i/h/e / other random little things that don't do much but get it running extra smooth. I am finally getting around to have some time to work out this tuning issue. I reprogrammed my wideband today since it was going all over the place before. I believe it to now be correct, since the idle hovers between 14:1 and 17:1 AFR. The issue is this:

I have the SAFC neo wired in properly (I know this because the signals are all correct, and the car runs as though it has no maf when it is unplugged). Furthermore, I have it set on 6 in 6 out for the throttle (which I believe is correct).

Bottom line seems to be that I have to crank the SAFC up to about +50 which is its max just to drop the AFR's from a lean 15-17 ratio that seems to be the ECU's default down to 13-15 range. Now I could be wrong, but this seems very strange. Should I be having to amplify the MAF signal this much just to drop the AFR's a little??

I adjusted my fuel pressure by routing the FPR to the pre throttle body side (which upped it to 35 psi). Supposed to be 36 according to FSM at idle. It was 33 when hooked up how it's meant to be which I also found strange. Am I just too low on pressure? Would an AFPR that can get me up into the 40 psi range solve this problem? Perhaps this? Or is there a cheaper way to boost pressure.

http://cgi.ebay.com/ebaymotors/B-FUEL-PRESSURE-REGULATOR-VOLVO-TOYOTA-LEXUS-NISSAN_W0QQcmdZViewItemQQ_trkparmsZ65Q3a16Q7c66Q3a2Q7c39Q3a1Q7c293Q3a4Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem3ca3fd06d1QQitemZ260449306321QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

To me, it seems like the SAFC can't lie to the ECU quite enough to get much more fuel out of it than is already there.

Now, I've been reading around and some people say the MAF should be 1in/1out and others say 6in/6out. Does anyone know of a definitive list or anything? It seems that if this is scaling the MAF signal as well, then it could be causing my problem. Or does it not matter as long as in/out are the same?

In and out settings are not the same for every car. You have to set it up to your car, not a generic 6in 6out or 1in 1out.

As far as the high afr's can't really help you there.

Yea, I am just doing some reading and figuring out that in = out does not change the signal. But by changing the in/out numbers I should be able to compensate and be able to add enough fuel.

It still seems strange I should have to do so much.

What kind of car do you have and what maf are you running?

B13 SE-R, stock maf. But hold on, I think I'm getting some stuff figured out now. I realized it might be close to correct, as a 30% increase in fuel should yield about 12.7 AFR if the ECU was aiming for 16.5 AFR. I just didn't realize the SAFC increments were in 1%, which isn't a lot.

Right now I'm running 30-40% increase and getting around 13 or 14. Car most definitely feels smoother to drive and pulls a little more, so I'm sure it's working right now.