VERY Strange issue .. Definitely need some input! Lean condition @ WOT

[BrianV8]

at full throttle you should also be seeing close to 4.5V think 3.99 is really low

[nelsonmxmarc]

I'm going to recheck my wiring to the resistor pack. A part of me tells me that it's not getting power.. Only thing is that it would certainly not run well, or even at all, so it's more or less a shot in the dark.

By turning the CAS i still hear every injector pulse, so there is power there.. I can maybe pull the plugs again - a rich condition (again) would ultimately leave me stumped, as there are ZERO exhaust leaks before the wideband, and the car is stumbling at idle (15-16afr).

One thing that i have been reading up on is injector resizing (Zach stated this).. When the injectors are resized, it only changes the K constant on the AFR maps, meaning the latency and pulse width are not altered. So any AFR value on the table is theoretical and can be off 2-3 points. Basically, and i'm not sure if this is possible, the maps reverted to stock pw and latency mid tune. The battery was on a charger for 90% of the time, which i personally hate because it leads to fluctuations in power throughout the system, so it's possible the ecu incurred some sort of overdose, either leading to electrical damage or possibly wiping out part of the map? These electrical systems are so fluky, its hard to tell what it is..

[BrianV8]

that was gonna be my next suggestion swap ecu's see what happens, look for codes

[nelsonmxmarc]

TPS voltage values are supposed to be ~.48 - 4v which i have. It reads higher on the multimeter, but consult allows you to see the real values.

Skym, good point. I never bothered to check the TP load scales on Nistune. It's quite possible i was never accounted for!

[nelsonmxmarc]

I can't swap ECU's.. Im running so many supporting mods that the thing would never run, and to find an ecu piggybacked with nistune suitable for my build is a 1 in a million shot..

[Skym]

Also could be a leaking intake manifold to head gasket or the fact that cylinders could be running leaner due to intake manifold design. Usually you have to run engine slightly richer to compensate for the lean cylinders with that type of intake plenum design, as there's no individual cylinder fuel trim on stock ECU.

[nelsonmxmarc]

Pressure tests on intake side show 20 psi of holding pressure (for like 15 - 20 seconds or so since i dont cancel out crank case pressurization) so i have ruled out all those possibilities. Plus a leak down tests shows no leaks on HG or valves/rings. I thought about fuel trim but AFR's are so rich (11) on the tables that to see 16 is a bit of an exaggeration

Going to revert to knock maps and see if it runs rich again, if so then we can rule the tune out as being the fault here.

[Black BNR32]

sounds like the tune to me

p.s. 15-16 afr during low load and part throttle is absolutely fine

[nelsonmxmarc]

Full throttle, 50 psi on fuel gauge, 19 afr.. No sense is being made here .. I'm seriously considering just ditching this project.. Haven't slept in 2 solid weeks, and no matter what I try there is no viable mechanical solution to this

[archaeic_bloke]

you need a fresh start brother...


Go home, and clear your mind by any means necessary just for 24hrs... It'll all still be there when u get back to it, and sleep. Sometimes sleeping on the problem u can dream up a solution.... u gotta take a break and approach it with a fresh mind man.

We're all pullin' for you on this one man, don't give up yet. The point of impossibility, is just that... A point, and on the other side lies success...

[cschepp]

Don't ditch it man, don't give up! You have put alot of hard effort into this and I would hate to see yo lose all of that because of a small problem. I know I can't really say much because I am selling my car but that is for different reasons.

[Black BNR32]

Full throttle, 50 psi on fuel gauge, 19 afr.. No sense is being made here .. I'm seriously considering just ditching this project.. Haven't slept in 2 solid weeks, and no matter what I try there is no viable mechanical solution to this

get a seasoned vet familiar with nistune and your engine to take a peak at the logs and settings?

[nelsonmxmarc]

So I reverted to knock maps, no difference, car won't stop running lean ..

All fuel has been changed;
Injectors/FPR/lines/filter/pump and pressure is fine
No leaks anywhere.. Timing is okay at 15btdc.. Tps is fine .5-4v..
Maf shows voltage so I can only assume it's okay..

????

[Zacho]

Now OK sure you are reading really high af ratios. But what is the car actually doing? At high 17 afr up and down my street when I incorrectly set my injector values (scale down instead of up WOOPS) my car hesitated when throttle was applied.

Maybe I'm crazy but I have a hard time believing almost 20afr at idle is an actual measured value. If this was the case, I would want to say something would be obviously wrong.

Where is your wideband grounded? When my wideband wasn't sharing the same ground (and I mean the SAME) as the ECU my readings were considerably off. Do the sensors require calibration/have been calibrated? My innovate requires an open air cal first use.

If you can, post screenshots of some detailed logs.

[MarusGTR]

^ Good theory. Don't give up.