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Installed Walbro 255 along with 560 injectors. Need help tuning for 18 psi.

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EagleTalonTim

15+ Year Contributor
830
13
Jan 10, 2007
Brighton, Tennessee
Ok, I just got done installing a Walbro 255 fuel pump and some 560 injectors. I set my SAFC to -23% for the low throttle all the way across the board, then I set the high throttle to -21% for any RPM above 2800. For some reason around 6000 rpm's it starts knocking in second and third gear. I have tried to add more fuel but that just makes it start sputtering and still knock. The sputtering is not fuel cut!

I currently have these things installed :
6 Bolt JDM Engine
Cyclone Intake set to activate at 3800 RPM
Evo III 16g
SAFC2
M/T ECU
Push button Shift Box
Rewired Pump (Walbro 255)
AFPR
560 Injectors
NGK BPR6ES gapped at 28
Brand new OEM O2 sensor ( < 3000 miles on it )
Brand new knock sensor ( < 5000 miles on it )

Everything else is pretty much stock.

Before I added the fuel pump and the injectors, I was running 450's on the stock fuel pump @ 15 psi with no knock at all. Any ideas on what is going on? Any adjustments I should make?

Here is the best log I took while test driving for about an hour :

RoadSurge.com - CSV Conversion for ID : 20

Thanks for any help in advance!!! I really want to get this tuned right soon.
 
Wheres the WBO2. This is why not having one is a bad idea because all you are doing is guessing. You pulled too much fuel out. Global correction I think is -14% for 550's. So pull 15% across the lo map and pull 10% across the hi throttle.

Drive around and get you fuel trims inline by adjusting lo throttle. Takes about a day or two. Once those are inline do some runs and start to pull fuel untill you knock.
 
If i could afford a WBO2 i would get one for sure :) My data logger has a WBO2 reading on it but I think it gets an estimated reading from the O2. It shows numbers from 0 to 255 so I am guessing 14.7 would be 128. No idea on that though.

As for setting it to -15 across the board.... Anything under 20 is making my Low fuel trim go down to -75 and my mids go down to -75. It seems the closer to 0% on the SAFC I go, the sooner the engine starts sputtering really bad. I have changed my spark plugs and wires about 1000 miles ago so I hope they are not fouled already. There are no major boost leaks. Boost leak test results are -5 psi per ~10 seconds
 
u realy realy realy need a wide band for wot pulls ,the oem o2 does nothing..... since your car looks to the ecu for the fuel and timing map. but you adjusting it w/o an wbo2 is just pure "guesstimation"... o2 are for close loop and fuel map is for open loop if i remember correctly... check the classifieds to find something reasonable never no what you may get. ...cheers.
 
I was able to get the fuel trims back to 100% according to the datalogger with the SAFC set at -23%. I set the high throttle setting to -23% up to 3400 RPM. After that I gradually went up to -19% but I still get 30 counts of knock immediately after I shift. I have to let off the throttle and get back into it to get rid of the knock. What is the best way to tell if it is rich knock? My O2 readings at WOT is .82v to .85v.
 
Global correction I think is -14% for 550's.

But he doesn't have 550's, I believe he's using the EVO 560's which seem to flow even more and also have a smaller deadtime. We can only assume he's running stock (for a MT) base fuel pressure. The deadtime will require pulling more fuel out at idle than at WOT. I change my NE points to get a 800 RPM point (the lowest a SAFC2 will go) so I can get the idle adjustment better.

While having a wideband O2 makes tuning easier, people managed for at least 10 years to reasonably tune these cars without one.
 
I'd say the safc is pulling too much timing, which is causing the car to knock and sputter like it's blowing out spark.
Happened on my buddies car they started adding timing problems went away and power started being made. Problem with safc is you can't mess with timing and when you mess with fuel trims the ecu automatically does it. I'd ditch safc and try one of the free programs or save up from link and wideband.
 
I do eventually want to get the link but I can't afford it right now. My goal is a 400hp daily driver but since this is my first time upgrading to injectors that the ECU can't compensate for, I need to learn the basics first with as little money spent. The timing starts out around 16 to 18 @ 3000 rpm and goes up to 23 to 26 @ 6500 rpm. I did notice on one of my logs that as soon as I shifted, my timing went to 8° while still at WOT. I know this is not good! I am so lost right now :p

EDIT *
My base fuel pressure is set at 43 psi at the moment. I turned the boost back up to 18psi after getting everything set to run at 16psi with no problems.
 
You need to turn your base pressure back down to 37psi or maybe a little lower. You are having to pull too much fuel out with the afc, which causes the ecu to use a lower load range on the timing maps. If you look at the last log, the point where you started knocking, you were seeing 25* advance. That's great for race gas or e85, but pump isn't going to handle that much advance. Turn the base pressure down, reset the afc to get your trims in line, and put an equal amount of fuel back into the higher rpm's and do another log and see where you are at.
 
ok, I just turned down the base fuel pressure to 36psi and readjusted the SAFC to compensate for the change. Instead of the SAFC being at -23%, it is now at -13%. I drove around for a bit to ensure the fuel trims were as close to 100% as I could get them and then did a few pulls. Here is one of the logs with the new settings :

RoadSurge.com - CSV Conversion for ID : 22

I still get knock exactly after I shift and to get rid of the knock, I have to left off the gas completely. If I get back into it again, it does perfectly fine until the next shift. I did notice that if I shift before 6000 rpms, there is no knock. Any ideas on this?
 
I ran Evo injectors for 2 years in my car using the SAFC-I

i did -18% across the board in the lo and got 20-22mpg.

set the hi to -8 across the board and tune from there.

i made 280hp easily on 18psi with a FP bigt-28 with those #'s i gave you.
 
Do you have race gas available near you? I would dump a few gallons in if you do and see if your knock goes away. It's possible that something is making enough noise for the sensor to pick up and cause phantom knock. Also have you checked your base timing? If you don't want to try adding race gas, you could also try backing off your base timing to 2* and see if it helps.
 
I do have access to race gas at the Memphis Motor Sports park I think. Not sure how much it costs though. I was wondering about adjusting the timing but I thought that if it was not at 5° TDC it could detonate the engine. As you can tell, I am new to tuning so I have alot to learn!
 
Your timing is really high up top. The 1g maps are very aggressive and adding a afc into the mix makes them more so. The base timing should be 5*BTDC so if you reset it to 2*BTDC you are taking 3* of timing out of the motor which should give you more room before knocking. And we all had to start somewhere.;)
 
I was able to get the fuel trims back to 100% according to the datalogger with the SAFC set at -23%. I set the high throttle setting to -23% up to 3400 RPM. After that I gradually went up to -19% but I still get 30 counts of knock immediately after I shift. I have to let off the throttle and get back into it to get rid of the knock. What is the best way to tell if it is rich knock? My O2 readings at WOT is .82v to .85v.

This makes me think you have phantom knock. Noise picked up at the knock sensor that is actually not detonation.

A good test is start real low around 2k at WOT. If you get knock release the gas and get back into it quickly. If it comes back and your still under 4krpms do it again. If its PK the knock should go away and not come back. If it goes away and then comes back you could probably say thats your actual knock since PK usually doesnt happen at higher rpms. Also if your sitting in neutral and you free rev, if you see knock you have a PK issue.

I have the this exact problem you explained. Here is a log I have of PK. Its at the very end so scroll till the end. Its exactly what you explain. At low rpms I get 5.6* timing pull and I release the gas and get back into it real fast and the rest of the log is free of knock. Sure signs of PK.
 

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The 1g timing map is pretty aggressive for 18psi as said. You may have to retard your base timing a few degrees, but that may not completely eliminate knock. Try to lower your boost to 15psi and see how that goes?
For reference, when my car was auto, I always seemed to pick up a few counts of knock when shifting but would go away shortly after the next gear began.
 
That is one of the problems I have been having is the shuddering or sputtering. The lower I go on the SAFC, the less it sputters but the more chances it has to knock. I do have a 2g MAF with the stock 2g intake pipe laying around ready to hook up but I never got around to it since the 2g pre-turbo intake is much smaller than the 1g intake. I will adjust the timing to 2 to 3 BTDC tomorrow morning and install the 2g MAF and see how it works out. I was running 15 psi with the 450 injectors with no problem at all. I wanted more power so I installed the 560's and upped the boost. That is when all hell broke loose and things went out of whack.
 
what is this supposed to mean?

"Keep going down until the ECU can no longer bring the A/F ratio back up to swinging in the middle LEDs (.2-.8v)."

Does that mean I have to adjust the SAFC so the ECU can no longer compensate for fuel adjustments made with the SAFC? I read somewhere that the SAFC is to adjust the air flow to keep the fuel trims at 100% which I have done.

I tried the "Basics Of tuning" link but the xls file does not work :(
 
what is this supposed to mean?

"Keep going down until the ECU can no longer bring the A/F ratio back up to swinging in the middle LEDs (.2-.8v)."

Does that mean I have to adjust the SAFC so the ECU can no longer compensate for fuel adjustments made with the SAFC? I read somewhere that the SAFC is to adjust the air flow to keep the fuel trims at 100% which I have done.

I tried the "Basics Of tuning" link but the xls file does not work :(

Did you read my post where I was talking about phantom knock. I have the same issue where you release the gas and it clears up the knock. Read my post thats a few above this one and look at my log.
 
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