bcrowley

Hey all, I'm new here.

I just picked up a 93 300SC with a 1JZ-GTE swap. It has a 67mm turbo on it. There is a S-AFC II and a wideband O2. The Wideband says I am running at 9:1 air to fuel.

I'm sure that reading is true because my sparkplugs look like charcoal.


I dont want to boost it unless I can have control over the a/f ratio.

I've gotten the safc programmed and it seems to be reading correctly. I know the MAP sensor is supposed to read between 1v and 5v. Mine seems to be hanging around 0.54v.

I cant make heads or tails of this safc as it seems any adjustment does nothing to my a/f ratio.


has anyone ever messed with this before that might be able to point me in the right direction?


Thanks guys.

bcrowley

Also, if anyone knows what settings to use for the S-AFC II on a 1jz-GTE motor, that would be very helpful.

purekoryo

bump, anyone?

ConSynX

iTrader: (1)

need to know injector size. . .

0.54v might be around 0psi, not sure if you set it so that you CAN'T boost, because you mentioned not wanting to. . .

you can PM me, but I'm about go to watch the Pens play...soooooo


If you injectors are >550cc, you will be better lowering the fuel pressure before tuning with the s-afc
I had ~680cc's and had kicked the FP down to 20psi@idle(w/ vac), and had the upper end around -26. This is with a gt4067.

When i was at stock Fuel Pressure, i was at -40...risky.

also, i don't feel 100%, but i'm thinkin the map sensor goes between 0 and 5(that's why i don't feel the 0.54v is bad). I dont have time to double check this, but people love correcting me, so somebody will post if this is not so.

GL, and Go Pens(Especially if you are a Flyers fan ).

ConSynX

iTrader: (1)

apparently since i was in a rush i didn't read some of your post. . .

If the AFR is not adjusting at all when you are playing with the s-afc, you may have a problem.

If you are testing it while the O2 sensor is in, and talking about the AFR AFTER a second or so, that is normal. The O2 sensor will automaticcaly take it back to around 14.7:1
If you are talking about WOT, then i'm a bit more stumped, unless your wideband max's out at 9 and just displays that for anyhting under, which means you simply aren't pulling enough yet.

plz make sure you did the initial setup of the s-afc correctly.(just noticed you asked for settings, lol) They are 6cyl, throttle is acending (up and right), and the MAP sensor is 1in and 1out.
Can't remember if there's more to set. . .

purekoryo

haha I was looking at the engine bay further and found that the damn O2 sensor is not in the down pipe (top mount manifold)!!! I went to autozone and ordered a 93 2JZGTE O2 sensor. I'm assuming this sensor will work? anything above 93 had 4 wires and the 91-92 only had one...weird. This car went through two owners previous to me in a very very short period of time and both saying that the car was running rich and was fed up with messing with it. If the O2 sensor is disconnected it would definitely run rich I presume.

ConSynX

iTrader: (1)

under regular driving, that is correct.

You might want to fix the settings a bit without relying on the O2 sensor, but that is preference, since the timing will be getting adjusted as well...like i said, fuel pressure ftw.

purekoryo

So any oxygen sensor from any vehicle would work as long as its 3 wire?

purekoryo

Oh and the injectors are yellow, which flow at 370cc correct? The fuel pressure will be turned up to 36 psi with vacuum once the o2 sensor comes in.

ConSynX

iTrader: (1)

I'm not completely sure on the O2 sensor. I google researched when I was buying it, but forget the info now.

1jz stockers are yellow

sc-driver

iTrader: (7)

Hey man, I remember when I installed my wideband and apexi afc neo that I would be getting really low AFR numbers too. The neo didn't really change anything while driving.

I found out that it was my ecu that was bad and that it was causing the fuel injectors to act weird and waste a lot of fuel.

purekoryo

If the oxygen sensor doesn't work I will try that. Thanks.

2jzlex

iTrader: (3)

Nope...... Lots of misdirection/misinformation in this thread too.

ConSynX

iTrader: (1)

buy the book How To Modify and Tune Engine Management Systems.

It's a good read and will help a lot.


btw, you never did classify if your low AFRs were under closed or open loop conditions.

purekoryo

It was and is still under open loop condition since there is no oxygen sensor ie. no feedback.

Actually I have some good experience with tuning cars, but thanks for the suggestion. I have tuned with SAFC's multiple times, Tuner Pro Rt, ECU flash, etc. But mostly it was with SR20DET's on both the 240sx and sentras (bluebird & gti-r motors) and EVO 9. I have never tuned inline six motors before, but im sure the fundamentals are the same. I have also tune SRT4's so I am also familiar with tunes based on MAP and MAF feedback. But I have only gotten up to 400whp on a 1996 4 door sentra with a bluebird SR20DET and GT2871r .86a/r turbo. My goal is to get 550-600whp with windshield washer fluid injection on this 1jzgte.