4.0L SOHC 4.0l SOHC tuning clippings and notes

[PetroleumJunkie412]

I'm watching, just don't have anything constructive to add.

I understand why at this point damn things can't tune themselves. Have basic parameters set to get it started (engine size, number of cylinders, sensors connected, ignition type, etc.) then once the O2 sensors warm up, let the computer learn everything from that. It should be able to build it's own damn tables. LOL

There are some people that have tried tuning with chatgpt/chatbots... results are dubious to say the least.

Some modern vehicles have "neural networks" now as well. I don't know enough about them to speak about them, though.

 

[PetroleumJunkie412]

Quick note on AFR:

SOHC has global AFR set to 14.68... ideal when gas was gas, but not now. Most fuel in PA is E10, some are now E15... E10 stoich is 14.07... so possible that the computer is always going for a slightly improper AFR as a result.

Here's an ancient forum about it:

using 14.047 for desired AFR and not 14.63? [Archive] - EFILive Forum

Before reading or responding please note the ? at the end. When we buy gas today it is very difficult to stay away from 10% ethanol. When setting up our tune we use an AFR as 14.63 approx for the most part and 1 for lambda and EQ. But what is the correct Base AFR to use with the fuel in the...

forum.efilive.com

May run a few data logs after wideband install to see if there's a difference when setting globals at 14.68 vs 14.07. Not sure if there will be one other than mildly increased or decreased fuel economy. Unknown if difference in knock sensors due to current inability to read the PID.

If I can just set my global fuel command to a lower AFR and the pcm will do it accurately, I have a very clear path for running 87 octane with 3.5 psi of boost pressure - just increase fuel globally in to overcome possible knock.

Tried changing my stoich global afr to 14.13 instead of the factory 14.68. Truck ran meh for 100 or so miles, then my trims started dipping into the -11+ territory.

Not certain why this one happened. It seems the pcm is programmed to bias towards the o2 sensors and trim around holding what they're reporting as stoich, which should be 14.7.

Need wideband.

 

[Roert42]

I noticed last night while messing around, base fuel table is already offset to accommodate for e10.

Not commanding full Lambda, this offset actually puts you just under 14:1

So theoretically shouldn't need to change the stoic to compensate for the e10.

Incidentally, I did the same thing and changed the Stoic to 14.1 and LTFT went from -3% to -6%.

 

[Roert42]

there must be some setting in the ECU that is conflicting with the commanded stoic value.

Something like, we changed what AFR we are using to set the base fuel tables, but not the desired AFR in closed loop?

I also wonder if it has something to do with the narrow band sensor not being able to properly read a 13.8 afr?


We may need to end up running fully in open loop on these if we need to modify the AFR significantly. Could just be a hardware limitation.



I have a book from LaSota coming dedicated to tuning Fords in HPTuners. I figured they were as good a source as any considering they worked with Moddbox to do tuning for their SuperCharger kits.

 

[PetroleumJunkie412]

there must be some setting in the ECU that is conflicting with the commanded stoic value.

I am starting to think this is completely true. I keep hitting issues that have no other explanation.

Will go into more detail this evening... need to test a few things.

 

[Roert42]

Briefly looking at a file for 4.0 mustang, there are a lot of parameters not available on the ranger version.

It looks like the mustang has a electronic throttle, electric fan, map, ect.

still spanish oak.

In the mustang file you have automatic shift points for WOT 4 Low vs normal WOT.

I think someone did a half a job when building the file for the ranger ECU.