I'll try to answer as much as I can here, it may be a lot to write lol. I am NO pro tuner, I am somewhat familiar with fuel injection and have been getting better with learning how to tune and read logs. I have extensively data logged this setup, probably 50+ logs over the past two years. I've had guys who know more than me look at it and the opinion ranges from "there's something wrong" to "the system is working as it should". I attribute a lot of the mess to E85, as there are many people who don't have good luck with this system on E. I'm hoping now on pump gas it'll be easier to figure out what's wrong.


I can actually post the data logs from the two drivers on these plugs in spreadsheet form if anybody here is willing to take a look. From what I have seen on previous logs, the ECU seems to be adjusting as it should. It had its weird moments and swings I couldn't figure out, but under throttle it wasn't maxing out learns or anything. I have yet to check these most recent logs.

As far as how it runs, I noticed no misfires at idle or with any decent amount of throttle. I have always noticed misfires when under VERY light throttle while cruising under load though. That's the only time I've ever felt/heard noticeable misfires.


The only spikes in the AFR's I have seen on pump gas were lean tip in issues which are common with FITECH and can be worked with by adding accelerator pump shot, and then the car seems to go EXTREMELY lean on deceleration. I know the FITECH has a DAFCO setting that I can shut off, but I almost feel like I'm going way leaner than I should even go with DAFCO when slowing down.

I guess I can talk about a lot of this stuff a lot, but if any of you guys are good at reading data logs I'm sure that will enlighten you a lot more than I can.


FYI, the bank my wideband is on is the 2/4/6/8 side where the plugs looked much more consistent. No exhaust crossover, so whatever is going on with that #2 plug in particular isn't going to affect the tune at all. I've never hooked a wideband up to that side to monitor. I've also never ran a wideband in the exhaust to see if the readings are anywhere close to what the FITECH is picking up, I'd love to do that soon.


I'm definitely doing the wires first. I just ordered Firecore wires from Mancini, hopefully I'll get them soon. As for ignition, I have a 6AL box that was on the car before, can't confirm it's good but it passes the bench test. Brand new MSD blaster coil, brand new MSD pro billet, phased rotor. Fitech controls the timing curve.


CSK, I totally agree. I found out very fast the "self learning" thing is a load of crap. There are hundreds of guys on the FITECH Facebook page constantly discussing tuning parameters. Turning the self learning off after a certain point is also very common. With that said, I realized a long time ago that this setup was going to take a significant amount of tuning to get right. I've learned/attempted a lot and I feel like I haven't made made much progress. It stood to reason that there may have been something else wrong, as no advice I have been given regarding the tune ever really helped. I even tried to bring the car to pro tuners but nobody wants to touch the FITECH setup which sucks.