Fuel trims...please help

[packinkimber45]

Hello everyone. I have been searching this site for the last hour and I cant find the answer. I just got my talon running by fixing my out of phase oil pump sprocket and set base timing to 5* btdc. I was using the logger tonight and under fuel trims (low,med,high) it is showing 81.2%. Is this good or bad? My mods are as follow:

Fuel: stock
evo 3 16g @ 10psi
stage 2 race head w/ mild port and polish
1mm oversized manley valves
evo 8 fmic
evo 3 manifold
3" VRS Exhaust
stock fuel pump
So since I am running 81.2% all across the board, does this mean I am running lean or rich? Logger says that the highest knock count I am getting is 2. When I log should I be only logging in 3rd gear and from what rpms to what? I dont have the program yet to download log to pc. As soon as I find out what gear to do a pull for logging I will download for others to see. I know I dont have any tuning abilities at this point, I just want to see where my car is at this point. So can someone confirm for me, do I do a 3rd gear pull and what rpm do I start at and what rpm to end at? Also during pull it should be wot right? Looking at my log on the palm here is an example;
@5093rpms
tps 96.4%
injd 75%
knck 0
o2-r .91v
tima 19*
isc 104
mafs 1599 hz
ftrl 81.2%
ftrm 81.2%
ftrh 81.2%
injp 17.9 ms

Another thing. When looking for knock is the important part is during wot? Is knock bad at all times? Reason why I ask is I've noticed that the highest knock I have gotten is 2, but looking at the logger it happens at low rpms. Also I noticed that knock will be more present during free rev than underload, is this normal? One last thing how can I make sure that my knock sensor is not bad? Sorry for the long post. I have a lot of uncertainties and all your feedback would be great. Thanks.

 

[Jst4Cyl]

There is a Word document that has all kinds of tuning tips on it floating around somewhere.... Knock is inevitable....The lower the better.....I think it has been said to shoot for around 7counts....I forget when the ECU starts pulling timing but this gives you a ball park....This is for 1G's........

As far as the fuel trims looks to me like you could run quite a bit more boost and not be maxing the injectors out....Depends on how the car runs to begin with.....I'd crank it up to at LEAST 15 psi and do a couple logs from 3500 to 6500 rpms...

I'd upgrade the pump to at least a 190lph and get you a fpr and work your way up the ladder of mods maybe even a rewire kit for now so you can possibly squeeze a little more fuel out of the stocker....As far as the knock count being so low I would say thats because your not really pushing the car.....

Good luck and have fun breaking it/building it/breaking it its a never ending cycle....

 

[Jst4Cyl]

Heres the file I was refering to...It's a word doc. Hope that helps you out....

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[packinkimber45]

So does according to my fuel trims I am running rich? Is that what numbers I am suppose to have w/ stock configurations? When I do my logs do I do 3rd gear pulls?

 

[tom04841]

You are running very rich. Fuel trims are supposed to all be as close to 100% as possible.

You don't have ANY fuel mods?

I would suspect a faulty O2 sensor or a minor exhaust leak before your O2 sensor causing your rich condition. If you have an exhaust leak before the O2, it can draw in fresh air and cuase a misleading lean condition to the O2. The ECU compensates by adding more fuel. If it was a boost leak, you would have trims over 100%

And yes, you should log you pulls in 3rd gear if possible. 2nd will do if you don't have a nice open stretch of road to do a 3rd gear pull safely.

 

[timloomis]

Yes, less than 100% means rich, more than 100% means lean. That's on high med and low trims only. O2 trim is backwards from that.

 

[Gstclipse69]

http://www.dsmtuners.com/forums/showthread.php?t=58403

 

[packinkimber45]

I just picked up the car recently and just a chance to drive it. So I understand I am running rich. On a 1g is that where the fuel trims are suppose to be at with the car stock? The fuel trims numbers I am seeing... are they the kind of numbers one would expect to have on stock fuel set up? No I dont have any fuel mods at this point and no tuning device such as safc. Reason for logging was to make sure car didnt have any issues that need to be addressed. Am I okay to be driving the car this way? Should I not drive it until I get safc and fuel mods? If not, what are some things I can do to be able to daily drive car until I have other mods? Should I take it pretty easy on the car? Also since I am running that rich does that mean the car could run a lot better once tuned with proper fuel mods, performance wise? If anyone see's anything wrong with the log I posted and my current set up with me driving it like it is pls let me know. This is my first turbo dsm so I dont want to mess anything up. I have been doing a lot of research and everything is pretty new to me. Thanks.

 

[packinkimber45]

You are running very rich. Fuel trims are supposed to all be as close to 100% as possible.

You don't have ANY fuel mods?

I would suspect a faulty O2 sensor or a minor exhaust leak before your O2 sensor causing your rich condition. If you have an exhaust leak before the O2, it can draw in fresh air and cuase a misleading lean condition to the O2. The ECU compensates by adding more fuel. If it was a boost leak, you would have trims over 100%

If the leak before the o2 is causing my rich condition, then how could that cause a misleading lean condition when it is running rich. I'm sorry I dont understand I guess. Thanks.

 

[tom04841]

If there is an exhaust leak, air will enter before the o2 sensor, the sensor will see the mixture as being lean, and the computer will dump in extra fuel to compensate for the "lean" mix.

The computer uses this feedback from the o2 sensor to determine how much fuel to add or subtract to acheive a mix of 14.7:1 AFR.

If you are the stock fuel system with no upgrades, you have a problem that needs to be fixed. You should be ok to drive, but also keep in mind that excessive fuel can cause cylinder wash which can lead to improper cylinder lubrication. That can cause your rings to wear faster, and can also cause scuffing of the cylinder walls.

Basically......find the problem and fix it.