Thread: +16.4% LTFT after Injector & MAF upgrade

Sup,

Just upgraded my **** to new injectors and MAF, re-tuned by Overkill (Scanned on, but canned tune still, I know.. I know..)

Mods are as follows :
XP Cam, SD Headers, 3.4 pulley, 4" intake with that big MAF Will have, #50 injectors, 180* and 104's gapped at 0.050.

My issue is mainly, well I'm trying to figure it out.
LTFT's are pegged @ 16.4% all the time beside at WOT, where they Lock in at 0.0.
STFT's at idle are 0.0% and bounces a bit between -3.0 and +3.0.
Driving they will wander about -3.0 and +14 ish.

O2's narrowband volts will be between 0.820 and 0.850 @ at WOT, which is lower than they were before the upgrade.

KR is higher than before too.

Now I know +16.4 is nearly always vacuum leak, first thing I did was carb cleaner all around, reseated injectors, cleaned holes SPOTLESS, no leaks were found that way, tried propane, nada. Lastly smoke tested the engine, build a presure in the motor with smoke, nothing came out at all.
Now I remember that on a vac leak, STFT's will bounce up to +25 too, when on my case they stick around 0.0 idling.

I am seeing with Will right now for a re-tune, as this, to me, might be the issue right now.

But if any one here has any other ideas, I'm a taker!

If your trims are locking in at 0.0 at wot they aren't learned yet. It takes 3 or 4 10 mile drives atleast to learn trims.

Sent from my SM-G920V using Tapatalk

the odds of getting 0 wot on the ltft from a canned tune is like a lotto number winning, not gonna happen.


trims go to zero wot while they learn, once they stop hitting zero they are learning at that point they can be neg or pos number, but you wont know till you get a few drive cycles on the pcm.

Drove over 200 km on it, 4 drives.
Working with Will to check out the tune.

What year do you have? 97s have an issue where that happens to them sometimes. I've seen it in person and tried everything to fix it tune wise, nothing worked.

04 Comp-g with mods in my sig

Something is off with your maf or injector data I would guess then. My comp g would go 16.4+ when I first tuned it for e85 and my skew percent wasn't enough. But it would also stay there cruising and since yours doesn't, it maybe. Something else. Have you set a code for fuel bank too lean yet?


Also on Tapatalk I can't see your signature. Sorry.

That's what I'm figuring, asked Will to redo my tune with the series of scanlogs I sent him.

Could you post up your scan logs here too? A few of us here are pretty decent tuners and might be able to lend a hand if we got a peak at the data. I know will is good (I got my first tune from him) but other eyes might spot something.

Also get a wideband installed. That data is invaluable.

Originally Posted by WolvesSoulZ

That's what I'm figuring, asked Will to redo my tune with the series of scanlogs I sent him.

do you have a tuner? hp or dhp? and wills making adjustments to the him as per the scans? if so that's the best route to take.


also if your cars not running well like exhaust leaks at the headers or a vac leak, the scans are giving you bad info. make sure the engines up to par for best results.

Vac leaks were tested, smoke test. So that's good.

Exhaust leak, SD headers flex is ticking and my flange down bellow too, but I think the rest is fine.

I don't have a tuner myself, nor DHP or HPT, which is something I have been telling myself that I should have bought 5 years ago, but yeah. Def. agree on the wideband though, that'll come soon. (Will should rent me one on the retune so we can get this **** at least sorted out.)

For those who wants to peak at the datas I recorded and sorted, here's my excel sheet ;
http://www.filedropper.com/scanlogcomplete34

Yeah I'd go with the HPT for sure

Just updating.
Will sent me a revised tune with the scans I sent him, fixed the LTFT's, fixed the KR issues I had (Obviously from it running lean)

Doubt it was a vac leak issue as now LTFT's are pretty close to 0 most of the range.

sweet. that was fast. guess it helps to live in the right country when using overkill.

Yeah me too, I usually do clean jobs when I do work related things around the car, I mean, injector holes were shiny when I popped in the new injectors.

Now just on to wait on the new belt to get here so I can get on the smaller pulley.

'Nother update,

The newest PCM with the right on LTFT can't hold an idle after the 4th drive cycle (Highway only run.) All between -3.0 and +3.0 at all ranges, including idle BESIDE highway speed, where they sat at +7.0.
Coming back up town, car began stalling at red lights and stops, even the next day.
And in park, idle, RPM surged quite a bit.

Re-tested for vacuum leaks with smoke, nothing again. Cleaned the new maf, tested by un-plugging and running without, car ran worst, so can't be it either I guess.

Re-plugged the lean-running PCM, first drive cycle on it, bit weird as always, but at least it held its idle fine.
The right running PCM had a funky idle since the begining though.

Running the car again on the lean running PCM until Will can get me back with it.
Guess I'll pull out the mastercard for Hptuner this time.