Ranger Mods

G'day guys,

i am new to forscan and still learning (reading and playing).My question is how do we look at short/long term fuel trims on px2?

Basically you don't. They will self learn and adapt where required. It is not a Toyota.

Info is held in the PCM DID blocks but you will not make much sense of it.

Daniel,
Good timing on this post.
Short and Long term fuel trim terminology is a petrol engine thing. Diesel motors don't try and run at a stoichiometric number so don't have AFR feedback to adjust fuel trim.
The self learning Stewart mentions above is an injector control mechanism to balance power output per cylinder (the PCM compares each cylinders performance).

Stewart,
Do you have an explanation of what the Service Tool Fuel Multiplier entry does and what the acceptable Fuel Balancing Quantity variation is?

FWIW, these are the numbers on my engine at idle (where it's more relevant) with ECT=41C.

Nothing at hand but put the numbers side by side and it will basically answer it. They are the same thing. One displayed in mg and one in % of 100. You can work the math break on it but visually you can see it where 0 = 100% and a minus mg less 100% and positive mg more than 100%. Why is it named that??? Will look through some docs at some point and see if I can find more info.

-0.04 98
-0.135 95
0 100
-0.025 99
0.2 107

Acceptable variation may be in the service manual but I cannot confirm.

Yeah, I saw that 0.030mg (or part thereof) = 1% deviation, after posting.
The doco I have says these balancing numbers (compensation) are only applicable (exist?) at idle. Presumably these numbers reflect a state of the engines mechanical condition. These seem to be a totally different thing to the pilot injection learned values which get assessed one cylinder at a time during engine overrun with zero pedal (Zero Fuel Calibration) and is meant to compensate for general injector wear.

I don't normally use FORscan to monitor, but it looks like I need to spend some time with it.

CatHerder wrote: ↑Mon Feb 22, 2021 3:43 pm Yeah, I saw that 0.030mg (or part thereof) = 1% deviation, after posting.
The doco I have says these balancing numbers (compensation) are only applicable (exist?) at idle. Presumably these numbers reflect a state of the engines mechanical condition. These seem to be a totally different thing to the pilot injection learned values which get assessed one cylinder at a time during engine overrun with zero pedal (Zero Fuel Calibration) and is meant to compensate for general injector wear.

I don't normally use FORscan to monitor, but it looks like I need to spend some time with it.

Nearly every available PID for these is in Forscan so it will always win over other software in that respect.

One day I will compare what is in there vs what I have on file and post the rest. It is very close to all available though for all modules.

Hi Stewart,

I've been trying to get info on acceptable Multiplier values with no luck.
Interestingly I don't have the Fuel Balancing value available.

I suspect an issue with one injector (possibly #3) but have no idea what the acceptable range for the Multiplier values.
So with engine coolant at 40 degrees And later at 79 and 81 to capture the variation in Multiplier values. Another 2.2 that I logged had Multiplier values closer to each other: Any ideas?

Nathan,
Were all mechanical (generally only A/C) and electrical (headlights, stereo, etc) loads always turned off for each log? These can greatly affect readings and make comparison with another vehicle hard. Auto and manual will also be different. Also, I think ECT needs to be around 80C not 70C for the ECU to consider the engine up to temp and at lower temps might apply different strategies so the other vehicle readings might not be fully relevant.
Having said that, there is some variation between injectors to get an even idle that might indicate some wear. How many km travelled on the injectors?

Hi Ian

My vehicle and the other vehicle had all accessories, lights, etc off and both manual 2.2.
I have 54000 km on the clock other vehicle 257000 km.

My two readings are at 79 and 81 degrees so at operating temp.
Other vehicle unfortunately cooled down by the time i got to datalog as I was doing some module changes for the guy.

Either way injector #3 is consistently low at each temp logged.

Interesting that there were no accs enabled on your car as the LOAD setting changed from 16 to 13%. Maybe it was jumping around? My rule of thumb would be <15% for an auto and <12% for a manual...(live and learn ).
To me (and I'm sure others will see things their own way) I would be wanting to operate within +/- 10% normally, so while #3 is outside that, #2 and #4 aren't far behind. At that point you have to look at other stuff like calculated LOAD, noise and driveability. Contaminated/wrong fuel might also have left consequences. If your concerned but car is driving ok, then log it with FORD if under warranty. If not under warranty find a mechanic you trust to evaluate the vehicle and provide guidance. Personally, I'd be logging to track changes but wouldn't be doing anything yet if the car is driving normally.

Interested in others interpretation.

I had a look at the log again and I probably live screen grabbed while it was still settling from ign startup.
The rest of the log the load remains around the 12-13% mark.

I have logged an injector issue since my first service and at every other warranty claim that the vehicle goes in for so that there is proof i flagged it.

They either won't give me their diagnostic readout, claim they can't hear the (noticeable) tapping sound, then next time they claim the tapping is normal then again next time they say it's because i removed the sound damper.
Which i did remove but only before my latest service as i found beach sand accumulated in there (and subsequent rust) from a coast trip i had done.
Gale force winds blew that stuff up in everywhere! Now i can keep the engine clean properly.

So I'm trying to get actual tolerances to work with and monitor that i can go and show the dealership.

I have discovered that I need to do the diagnostic work for these modern so called auto tech's employed at some dealers.
Otherwise they find the easiest, least effort reason for the problem as they have zero diagnostic skill besides what a computer can tell them.
As an example:
I had to measure my rear axle side shaft flange runout on both sides, film and present as evidence as to the cause of my vehicle "bouncing/vibrating" at certain speeds. They would come up with excuses like tyre pressures, tyre damage and "road not smooth, you know"!! etc
Only after my diagnostic work did they call a Ford "engineer" in to check and authorise a replacement and he didn't do his job properly either as there was now an issue with the drum itself as a result...