2g logging for the first time please help

[cuong1106]

hey guys i was trying to tune my car yesterday with the new logger i bought. im tuning with the tunerstein program and using a palm also. some mods are 50trim turbo, 3in dp and exhaust, external gate, 3in intake, fuel is 660cc and a 180lph pump. currently i have the safc at -18 on the low settings as well as the high settings. well while i was trying to tune the short term fuel trim, i was monitoring the RPM, AIRFLOW, and SHORT TRIM. the short trim was at a positve 17. and while i was reading Kyle's guide to tuning. it said i should add more fuel if the number was positive, so as i was adding more fuel at the 1k range on the safc it was getting closer and closer to the positve range. wanted to know if im going in the right direction as far as tuning and what else should i be doing? is it even possible to be +or- 5 percent on the 660cc? i dont have a hacked MAF either. please any help is appreciated. thanks cuong

 

[Blk_99gst]

Now, look at the low fuel trim (2g's only have the LTFT). If it is positive, add a few percent on the SAFC at the 1000 rpm point. This is not an exact science, but usually for about every 3-5% on the logger, you need 1% on the SAFC. After adding or subtracting a few percent, let the car idle for a few minutes, and watch the fuel trims change. This may take a while, especially in a 1g, so just wait.

The above is from Kyle's tuning guide. I guess it is a little vague on which way to tune, "if positive, add a few percent on the safc". Depends if "add" means to lean or richer things out. Anyway, I'll explain it here for you.

For low safc tuning, you'll want to use the "view" function and look at STFT, LTFT, tps, timing, o2 bank 1. Mostly we're looking at LTFT and STFT. The way the ecu works is after combustion, it looks at the o2 values, and then adjusts the fuel trims to try and acheive the perfect ratio. If things are too rich, then the safc will use negative fuel trims to take out fuel, ie. fuel trims could be -10 or -15%. If things are too lean, then the ecu will use positive fuel trims to add more fuel, ie. fuel trims could be +10 or +15%.

So re-reading your post, I'm confused. You have 660 injectors which are like 30% bigger than the 450 injectors. You have -18% on the safc, and you have POSITIVE +17% stft from the ecu? That +17% is saying things are too lean and the ecu is having to add 17% more fuel. Which just doesn't seem right at all. If anything, you should be in the -25% to -30% on the safc range. What do LTFT say, it's better to go off those then STFT sometimes.

Also did you reset the ecu after the injector install? It might be necessary to do that again here soon. Better yet, did you install your injectors or did someone else? If you say someone else, are you sure they put them in? Say you still had the stock 450's in there, and then you did -18% on the safc. The ecu would compensate by doing +17% on its fuel trims.

 

[cuong1106]

Well on kyles guide it told me to lean out the safc settings -18 all across the low and the high settings, which i did. and now when i hook up the logger to the obd2 port and run it, the stft reads positve 17 and the ltft reads bout a positve 17 also. and when i start adding fuel, which is going towards 0 on the safc, the number on the logger gets smaller and smaller. i did reset the ecu after the injector install and i reseted the ecu once again because i had to to my battery out and recharge it. i installed the denso 660cc injectors myselft also. and the injectors does say denso on them and they are blue in color. please help me kinda stumped on what to do. by the way which part of texas are u located? in about an hour east of houston. do u have a aim account where u can be reached? thanks cuong

 

[CanadianTSi]

-18 is just a general number, each individual car will be different.

Just follow the guide untill you get your fuel trims as close to 0 as possible.

 

[Blk_99gst]

Hmm, very strange. Sounds like you are doing everything right; reset ecu after installed and followed the tuning guide. I would sugguest this: Warm the car up to normal operating temp. Shut it off. Zero out the safc, reset the ecu, and turn the car on with the logger ready to go. STFT and LTFT will be zero after an ecu reset, so when you turn the car on, the STFT should shoot to it's max of -24%, trying to remove the gas that the 660's are pumping out. The car might even have problems idling because it won't be able to remove enough fuel. That's what SHOULD happen. If instead you do the above and the stft only moves a couple of % in either direction, then you do NOT have 660's in there.

I've got denso 660's too, and just went back to using my safc to control them. My safc low settings are sitting at about -28%, and my high's are in the upper -30%. Again all cars are different, but you should be well into the negative 20's on the safc and almost zero or still in the negative % of fuel trims.

I'm in austin; so we're probably pretty far apart. Sorry, no instant message. Just email and pm's. So try the above and let us know how it works for you.

 

[cuong1106]

well reseted the ecu like u asked me to after warming up the engine, also zeroed out the safc settings on the low and high side. and then i turned the car back on and i waited for it to idle all good. but still i get no -24 on the STFT. i think it around zero on the logger if the safc is zeroed out. would a intake leak or vacuum leak cause something like this to occur? please let me know. i know for sure they are denso 660cc cause the person i bought them from said they are and i gave the part number to rre before i installed them and they confirmed that the part number i gave there were indeed for the 660cc. thanks please help me

 

[Blk_99gst]

Man, I don't know what to tell you. What you put in are just not 660cc injectors. If the car is running fine, and stft's (after the reset and w/safc zeroed) are near 0%, then those would be like stock 450's. The ONLY way those could be 660's with your safc zeroed out is if you had a different ecu chip that had been pre-programmed to compensate for larger injectors; and since you didn't mention that, and you just swapped out the 450's for 660's then my guess is you don't have that.

And a boost leak or any other leak wouldn't cause that. If you have a boost leak, then you have already metered air escaping, so the engine is going to run rich because fuel is being added for air that has already escaped.

You say that you ran the part number to rre; was this part number off the injector itself or off the already opened bag that the used injector came in? If I were you, I would contact whoever you bought the injectors from and tell him you don't think they are 660's. The ONLY way to prove what the injectors are would be have have then re-balanced and flow tested. Having them flow tested will tell you how many cc's they are putting out. I don't even know if I would go that far. I would just try and get my money back. I just hope the seller doesn't try and pawn them off on some other dsmer. Do you know this guy? Is he local? Was he parting out his dsm or is it still running? If his car is still running, ask him what his injectors are, what his safc settings are for his car. Maybe he got 660's for himself, and then put his 450's in the 660 bag and sold them as 660's.

 

[cuong1106]

well the injectors i bought were from a lady in utah that goes by the aim secongendsm. she is a very knowledgeable person, her and her husband. and the part number was the numbers off the injector itself. and i dont know what the part number off the top of my head and i dont remember saving it either, but once rre confirmed that the injectors were denso 660cc i installed them and never thought anything of it. the injectors are have a BLUE top and they have the name brand of DENSO on there. so im pretty confident that its the 660cc and plus rre confirmed it. do u have ur part number of the densos? thanks please help

 

[Blk_99gst]

Why do you think she is a knowledgeable person? Just curious. I guess you've only got two options in my opinion. So you did the test with the 660 injectors after an ecu reset and safc zeroed out. You could put your old 450's back in and do the same test, car warmed up, reset the ecu, safc at zero, and watch the fuel trims. If the fuel trims don't move anywhere (and they shouldn't since we're back to stock), then that's saying that your 660's and 450's performed the same. And we know for a fact that your 450's are 450 since they are stock on our car. The 660's are the ones we're not sure about. Or option #2 would be to have them flow tested. That would give a cc rating for each injector. Or try putting your 660's into another friend's car. They don't even need a safc, just reset their ecu and watch what their fuel trims do.

I saw your link and my denso 660's looked very similar to yours. But then again all denso injectors (550, 660, 720) look the same I believe. I don't know if denso makes 450's in the black color.

 

[Violater101]

Why do you think she is a knowledgeable person? Just curious. I guess you've only got two options in my opinion. So you did the test with the 660 injectors after an ecu reset and safc zeroed out. You could put your old 450's back in and do the same test, car warmed up, reset the ecu, safc at zero, and watch the fuel trims. If the fuel trims don't move anywhere (and they shouldn't since we're back to stock), then that's saying that your 660's and 450's performed the same. And we know for a fact that your 450's are 450 since they are stock on our car. The 660's are the ones we're not sure about. Or option #2 would be to have them flow tested. That would give a cc rating for each injector. Or try putting your 660's into another friend's car. They don't even need a safc, just reset their ecu and watch what their fuel trims do.

I saw your link and my denso 660's looked very similar to yours. But then again all denso injectors (550, 660, 720) look the same I believe. I don't know if denso makes 450's in the black color.

What's curious is that his O2's @9spi were like 1.12V's which doesn't jive with his readings that he is getting on his fuel trims. Is there a way to log Injector Pulse width with the Tunerstein on a 2g? Is this the samething as load? I was looking at the tunerstein website and wasn't sure. I saw it listed for 1g's.

 

[cuong1106]

well i called roadrace and they confirmed that the denso 660 injectors are the dark blue color which i have in my car, the 550 are purple in color, and the 720 are a light blue color. and that lady that i bought them from is a knowledgeable cause she and her husband owns 2 dsm that runs 11s and such. they did a 6bolt 2.4 swap and the such also. so im assuming that she knows what she is doing. and plus with the safc at about - 24 across the boards on the low and high settings at 9 psi the o2 voltage was about 1.12v. and when driving the logger would drop to negative values such as -14 and the like. why is that? if i have high o2 voltage with those types of fuel trims? please respond asap. thanks cuong

 

[Blk_99gst]

What's curious is that his O2's @9spi were like 1.12V's which doesn't jive with his readings that he is getting on his fuel trims.

That would be true. I take it the 1.12 o2 volts was during a wot run or something. Your right, that doesn't jive with fuel trims not moving.

Is there a way to log Injector Pulse width with the Tunerstein on a 2g? Is this the samething as load? I was looking at the tunerstein website and wasn't sure. I saw it listed for 1g's.

No, us 2g's can't see injector pulse width.

 

[Blk_99gst]

well i called roadrace and they confirmed that the denso 660 injectors are the dark blue color which i have in my car, the 550 are purple in color, and the 720 are a light blue color

Didn't know that; that's good info.

and plus with the safc at about - 24 across the boards on the low and high settings at 9 psi the o2 voltage was about 1.12v. and when driving the logger would drop to negative values such as -14 and the like. why is that? if i have high o2 voltage with those types of fuel trims? please respond asap. thanks cuong

Hmm, you never mentioned that you did (I assume) a wot run with -24 on the safc high's and were getting 1.12 o2 voltages. And you didn't mention that when driving (still with -24 on the safc?) that you had negative fuel trims.

So let's assume they are 660's. Then why don't you warm up the car, reset the ecu, set the safc at -20 across the board, and then go and drive at 50mph and then see what stft are doing. They will probably be negative, and you will have to lean out the low table a little more.