S-AFC II Tuning Help!!

[junior929rr]

I have used the search button several times and have taken info from other threads, but I am still not having any luck. I want to apologize for the length of this thread up front, because I know I have a lot of info to cover. I am about to pull my hair due to multiple failed attempts at dialing in this car.
1997 GSX.

Here are the list of mods:

Stillen Intake
FP Big28 Ported, ported O2 housing
3 inch DP (no cat)
HKS Super Dragger Exhaust
Greddy FMIC
Dejon Tool upper I/C pipes
HKS SS BOV
Walboro 255LPH fuel pump
NRG Fuel Pressure Regulator
550cc injectors
S-AFC II
NGK Iridium Plugs
NGK Wires
Autometer boost/vac
Autometer EGT
Autometer A/F
Road Race Catch Can

First off, I have not messed with the MAF sensor (honeycombs all in). A friend and I have been working on this car on and off for over 2 years. There was a point where we had the low-throttle dialed in (all 0 trims) and were working on high throttle. We felt we were almost there, but then winter came, the car was put in storage and we decided to start fresh in the spring. We have been trying to dial in the Low Throttle Settings with no luck. Even when both trims are at 0, it still runs like crap. I’m pretty sure the car is trying to drown itself in fuel, as it keeps requesting more fuel, even when the car smells like gas and is a complete dog in the low RPM range. When I get on the throttle EGT’s are also much higher then they were prior to the injector/S-AFC install. EGT’s reach 1500F by 5300 rpm. A few weeks ago we had the low throttle zero’d out and moved on to high throttle. When I logged timing, it had been dropping down to low single digits when I would punch it, then only coming up to around 11-12 degrees of advance. The O2 Volts stayed around .98 for the entire pull. I then got disgusted with the driveability and decided to start over. ECU was reset and low throttle settings were dialed in. I drove it about 10 miles and it seemed decently smooth. After the 10 miles it started to pop and chug when I would roll on the throttle at 2K.
Also, I set the FPR for 43.5psi and had noticed it went up. I lowered it back to 43.5 then after driving it, it reads 40psi at an idle. I am not sure if I have this hooked up correctly? I have a vacuum line running from the FPR to the throttle body. The electronic solenoid that went to the factory FPR is still clipped in, but capped off. Is this correct? Any help on this would be greatly appreciated!!

Also, the car has 24K on it and recently passed a boost and vacuum leak test.

Low Throttle S-AFC Settings
1K +10
1.6K +11
2.2K +9
2.8K +9
3.4K +9
4K +9
4.6K +9
5.2K +9
5.8K +9
6.4K +9
7K +9
7.2K +9


Again, any help would be greatly appreciated! Thanks.

 

[GVR4592]

The fuel pressure regulator needs to be connected to a boost and vacuum source. I would move it to the intake manifold and see if that helps. Make sure you set it for 43 psi with the vacuum line disconnected.

 

[compression]

I have used the search button several times and have taken info from other threads, but I am still not having any luck. I want to apologize for the length of this thread up front, because I know I have a lot of info to cover. I am about to pull my hair due to multiple failed attempts at dialing in this car.
1997 GSX.

Here are the list of mods:

Stillen Intake
FP Big28 Ported, ported O2 housing
3 inch DP (no cat)
HKS Super Dragger Exhaust
Greddy FMIC
Dejon Tool upper I/C pipes
HKS SS BOV
Walboro 255LPH fuel pump
NRG Fuel Pressure Regulator
550cc injectors
S-AFC II
NGK Iridium Plugs
NGK Wires
Autometer boost/vac
Autometer EGT
Autometer A/F
Road Race Catch Can

First off, I have not messed with the MAF sensor (honeycombs all in). A friend and I have been working on this car on and off for over 2 years. There was a point where we had the low-throttle dialed in (all 0 trims) and were working on high throttle. We felt we were almost there, but then winter came, the car was put in storage and we decided to start fresh in the spring. We have been trying to dial in the Low Throttle Settings with no luck. Even when both trims are at 0, it still runs like crap. I’m pretty sure the car is trying to drown itself in fuel, as it keeps requesting more fuel, even when the car smells like gas and is a complete dog in the low RPM range. When I get on the throttle EGT’s are also much higher then they were prior to the injector/S-AFC install. EGT’s reach 1500F by 5300 rpm. A few weeks ago we had the low throttle zero’d out and moved on to high throttle. When I logged timing, it had been dropping down to low single digits when I would punch it, then only coming up to around 11-12 degrees of advance. The O2 Volts stayed around .98 for the entire pull. I then got disgusted with the driveability and decided to start over. ECU was reset and low throttle settings were dialed in. I drove it about 10 miles and it seemed decently smooth. After the 10 miles it started to pop and chug when I would roll on the throttle at 2K.
Also, I set the FPR for 43.5psi and had noticed it went up. I lowered it back to 43.5 then after driving it, it reads 40psi at an idle. I am not sure if I have this hooked up correctly? I have a vacuum line running from the FPR to the throttle body. The electronic solenoid that went to the factory FPR is still clipped in, but capped off. Is this correct? Any help on this would be greatly appreciated!!

Also, the car has 24K on it and recently passed a boost and vacuum leak test.

Low Throttle S-AFC Settings
1K +10
1.6K +11
2.2K +9
2.8K +9
3.4K +9
4K +9
4.6K +9
5.2K +9
5.8K +9
6.4K +9
7K +9
7.2K +9


Again, any help would be greatly appreciated! Thanks.

ok first of all, you have larger injectors and fuel pump , so you should not be adding fuel anywhere. try going to -5 across the board or something and leaning it out from there.

 

[hottboost]

Ive been working on getting mine tuned! Ive been able to get some nice logs @ 20PSi, so heres my settings but please remember that every car will be different. We have close to the same mods except Im still on the stock SMIC.

Hi Th
1000 2000 3000 4000 4500 5000 6000 7000
-13 -13 -15 -18 -18 -19 -18 -19

Lo Th
1000 2000 3000 4000 4500 5000 6000 7000
-12 -07 -09 -09 -09 -09 -09 -09

Th settings 30% - 80%
Have never touched Honeycombs or mas! Hope that helps!

Heres the log with those settings
Made 5 pulls with very similar log and EGT'S never got above 820 C

rpm timing o2

3052 13 0.91
3192 10 0.91
3328 09 0.93
3520 06 0.95
3716 08 0.95
3924 10 0.95
4120 10 0.95
4324 10 0.95
4488 10 0.95
4664 10 0.97
4852 11 0.97
5036 11 0.97
5152 12 0.97
5360 13 0.97
5516 15 0.97
5644 16 0.97
5788 17 0.97
5944 18 0.97
6104 19 0.97
6240 19 0.97
6368 20 0.97
6464 20 0.97
6608 20 0.97
6736 20 0.97
6820 21 0.97

 

[junior929rr]

Thanks for the responses! I do have the FPR hooked up to the intake man., but for some reason wrote throttle body. I will try adjusting it again with the vacuum line off. As far as the S-AFC, every time I have reset the ECU and started at -10, and to get the trims to "0" out have ended up in the positive...which doesn't make any sense. Any ideas as to what would cause the car to demand more and more fuel?? Like I said, just did a boost/vac leak test and no leaks. Thanks again.

 

[kelvinb]

fuel filter ok?

 

[junior929rr]

Hmmm, I'll try that. It can't hurt to replace it since it is the original fuel filter. What doesn't make sense is that the car smells like gas when it idles/drives so I would think that it is getting enough fuel...??

 

[spectr019]

Just a thought, but do you still have the cat on the exhaust? After you take that off, you'll sometimes feel like your in an old V8 cause you are inhaling all the good stuff found in 93+ octane fuel
Again just a thought, but with all the fuel work you've done on the system, it's a pretty small thought. Good luck.

Ben

 

[spectr019]

I just re-read your mod list. "no cat" I missed that one before. But yeah, that's a possibilty

 

[junior929rr]

OK, time to pick some brains. I replaced the O2 Sensor, thinking maybe the O2 wasn't reading correctly. Nope, I still have to add fuel (anywhere from +6 to +10 across the RPM range) to get the fuel trims to zero out. I'm wondering if I actually rec'd 550cc injectors? I am going to put the stock injectors back in and see what happens. Also, I set my FPR to around 43 psi with the vacuum hose off. When the vacuum is applied the gauge reads about 38 psi. Is this the correct way to set the FPR? Thanks in advance for any replies.

 

[junior929rr]

More info:

I swapped out the 550cc injectors and put the stock injectors back in, just to see how it would effect the fuel trims. Here are the corrections on the S-AFC to zero out the fuel trims.

550cc injectors Stock Injectors

1k +14 1k +9
1.6k +15 1.6k +7
2.2k +14 2.2k +8
2.8k +11 2.8k +7
3.4k +12 3.4k +6
4k +12 4k +6

From what I know, this is totally backwards. Is it possible to wire the S-AFC incorrectly and get this effect? Maybe the injectors I received weren't actually 550cc? Any ideas????

 

[junior929rr]

Double checked the S-AFC wiring and it is correct. Is there any way to verify what size injectors I have? They are Lucas 550cc injectors...well they were suppose to be.

 

[siceclipse]

i would set your Low to -15% across the board seeing how 550's flow 18% more fuel then the 450's/

then leave it alone for a gas tank or 2 to give the OBDII time to learn and catch up.

then go from there.

I had my SAFC set to -9% and my EGT's skyrocketed because of all the extra fuel combusting in the Exh. Manifold.

when i took more fuel out my EGT's went to 1350-1400 part throttle on the highway at 75mph.

For refrance, the equation is:

OEM INJ / NEW INJ = X

1-X=Y

Move decimal of "Y'' 2 places to the right and thats the % bigger than stock


450/550= .818181818

1-.8181818181= .1818182

Move Decimal= 18.18% larger than stock.

Rep point like WHOA

Following this made me go from -9% to -16% on my low.

Right now my ECU is bugging out cause its not used to pulling that much fuel so its gonna take time to learn that its now the new "norm"

 

[2gGSX]

The above derivation is correct--you should technically take out -18% globally on 550cc injectors. Any changes in EGT readings is more likely due to a difference in timing--which has a much more pronounced effect than AFR. With more airflow reading taken out you will trick the ECU into adding more timing, which will decrease your EGTs.

 

[spyderturbo007]

Everyone above is correct, you are adding way too much fuel on your high throttle map. Also, throw the iridium plugs in the trash and get some "normal" NGK's.

 

[Raph]

doesnany one experience the following with heir safc ?
(no need to start a new thread)

its a 4g63 nt which originally had 240cc ..now using 490 cc injectors..

well.sometimes in 4th and 5th gear..if rolling at like 3-4k rpm and i suddenly push the clutch,the rpms drop all the way down and the car dies.. then ill have to crank it for 30 secs for it to come back on.. the only way if found to combat the problem is to put the car in neutral and blip the throttle.. or push the clutch in below 2000 rpms..

this only happens on decel .

does the decel air settings have anything to do with this? i havent played around with them.