I created a log with my Predator at 1950 RPM's, and my LTFT's on both banks average in the 8.5 range. Ran the data as a CSV file through Redux, and it recommended I set my injector slope to -9, to compensate. Since optimal LTFT's are around 0 to -1, does that make sense? Only thing i've got done to my truck is a K&N filter, stock air box, and i'm running a strait pipe. Oh, and the high octane predator tune. (that was probably obvious) Even still, I thought my LTFT were a little high.

Thanks,

 

Take note of the stft and then clean your MAF. Basically Idle the truck for a minute or so after is warm and watch what the stft are doing. +/- 5 is what your looking for. Once you know what the stft are doing shut the truck off get some electrical cleaner/MAF cleaner and clean the meter. Once you've cleaned it check the stft again and see if they are where they need to be. Don't worry about ltft because they are based off an average. That includes when your driving down the road. Thats where I would start. Hope that make sense.

 

If you go onto DS wesite they have a forum. If you ask them a ? they will walk you right through it. The idea is to get as close to 0 as possible. My truck has a CAI, Muffler, Diablo tune and i had to go to -8 to straighten them out. Then i hooked up with Lew and got a custom tune. WAYYYY better!

 

 

At -9, my truck was bogging, like it was getting way too much fuel. I tried running a couple more logs, and for some reason, the dataviewer was not picking up the LTFT's at all. I was at the correct RPM and all. I posted this question on the Diablo website, and it's been there for a couple days, but no answers. I can't figure out why it's not logging the damn LTFT's. I was watching the STFT's real time, and they really looked pretty good.

I know Lew is what's up, but I can't afford the price, even though it's not high. I just simply don't have it right now. I've had to buy tools and **** I wasn't expecting to for other install items on my truck. Looks like i'm stuck waiting on RPMoutlets tune. They are just kind of a pain to deal with, but the tune will be free, which is what I can afford at this point. I can't install my headers until I get the tune from RPM.

I just wish I knew why I can't get the software to log my LTFT's. Not only did my truck loose power when I set the injector slope to -9, my gas mileage got cut in HALF. I was like, WTF????? When I defaulted back to the stock canned tune, all seems well.

 

think I just replied to your post on the dslogredux forums, right??

dude... you're chasing your tail...

the ltft's will always change depending on weather/outside temps...

ideally, you want to do it during a warm summer day - 85* - do a log, see where your ltft's are at... make the adjustment so that your ltft's are in the 0 to -2 range for that weather, and then that's it... leave it alone... no need to change anymore...

the purpose of fuel trims is to change/fluctuate... but the idea is, you don't want them to be any lower than -2.xxx during the warmest weather for your area...

after that, if they go a little positive, so what....

mine do.. during the winter here in CT, my ltft's are +3's... I do not adjust for them...

come summer time, they're right back down in the 0 to -2 range...

that's it...

you keep checking 'em like you're doing, and you'll go nuts...


or, get a custom tune done for your truck and get the MAF sensor re-scaled...

 

Thanks Lew. I've got the "new toy" syndrome right this second, and because of the mods i've been doing to my truck, and the overall purpose of those mods, i've been a bit obsessive. I just want to make sure i've got it dialed in and it's performing the best as could be expected. And I wanted to be able to provide feedback to the other truck owners on what I did, my successes and failures, and what worked for me and what didn't. When you don't have a bunch of cash to blow, it's important to get it done right, the first time. That includes having the right tools when you tackle a job, having the right parts to complete the job, and being able to dial it all in. I'm preaching to the quire, but someone that doesn't have a clue wouldn't understand that. All my questions and trials might save the next guy a few bucks, or maybe a few hours of labor, and hopefully, add a few MPG's and HP to their motors.

 

So have you got it all figured out? If you can afford it i recommend Lews tune! Makes the Diablo tune feel like stock!!

 

I haven't messed with it again. I got frustrated with the datalogging software when it wouldn't record the LTFT's for some reason, and it's been running so well with the restored canned tune, I just left well enough alone. Besides, i've got a custom tune waiting on me in my inbox from RPM. They were slow, but delivered on the promised tune.

I needed the tune because of an up and coming long tube install in a couple weeks. I had intended on putting the headers on this past weekend, but the wrong muffler showed up, so i'm back to waiting again. It should be in today, but I have to wait a couple weekends so my money is back right, and i've got the time. Not taking any chances with a header install, too much can go wrong........

Since i'm deleting the cats w/ and offroad Y, and long tubes, I needed to have my **** together. I'm hoping to see some big gains with the headers and the final set up. Here's a little info....I'm currently running a strait pipe, K&N filter w/ stock air box, Powerbond underdrive pulley, and the canned predator tune for high octane fuel. Running 93, I've already put 100 miles on my truck (X cab 2wd 1500), and my gas needle has barely moved, just below the F mark on my gas gauge, but it's still touching it. Can't wait to see what it does with the headers. I'm also putting new plugs and wires on at the same time, since it's due a tune up. 22 MPG in the city with a 5.3? I think it's possible.......

 

Wow thats asking alot. I'm lucky to get 24mpg on the freeway babying the hell out of it. Let me know how the tune comes out from RPM. I've noticed alot more power and mileage out of my mods. I am waiting to get some extra cash to put some headers on my truck.