Ranger Mods

Hi all.
Anyone know if there are any parameters available in Forscan to limit the range of operation of the intake throttle valve?
Tuners did an EGR disable but the throttle plate continues to close close down at low load which causes manifold vacuum and high EGT.
Have unplugged the throttle body so it remains wide open. Far more responsive now but i still want it to close down when i turn the ignition off.
If i cant adjust parameters I can intercept the throttle body signals with an Arduino, but I'd prefer an easy solution.
Cheers
Peter

NO, either do your Arduino or re enable and fit catch can.

Remove butterfly

Or get your tuner to fix it. Sounds like only half a job has been done.

Like most, routine for EGR will just be disabled so without rewriting multiple parts of the calibration so a proper tuner fix would be unlikely. I would even go far enough to say a tuner fix will not happen at least in Australia due to lack of knowledge.

Thanks for feedback. I have certainly learnt a lot about modern diesels in this experience.
Saeb you are right that there really is a lack of in depth knowledge and nobody in aus that can edit more than the maps they are given in the tuning software.
The performance and response though with EGR blank and throttle plate wide open at all times is absolutely amazing (other mods too obviously).
I'll know next week if i have to pursue the Arduino method. Will update if ur interested.

Whether some decide to follow or not follow your lead, still post an outcome as at some point it will either answer or give a solution to someone with the same issue.

I've been doing a fair bit of data logging over the past week and - at least on my PX3 - the throttle plate doesn't get used much at all; just to assist with EGR (which runs almost all the time) when exhaust back pressure is lower and boost is up. Maybe with EGR disabled it's being more active? (the PCM has a routine to detect if the EGR is contributing to air going into the motor, and I doubt any tuning software provides these tables to edit)

I agree that closing the throttle plate on engine OFF is a good thing.

the anti shudder valve serves to stop the engine from shacking violently on engine shut off.this is due to diesels not having a throttle body
and air still gets sucked into the cylinders and you still get some firing happening.
the anti shudder valve is spring open electrical drive shut.
it does not modulate when your engine is running its open or closed. default position is open ( or fail safe mode )spring drive open
modern diesel use the accelerator pedal resistor to tell the ecu to add fuel in conjunction with the maf sensor and IAT sensor
if it modulates then then it is getting a signal from the ecu to do so.
the EGR is vaccum controlled via the ecu
diesel engine use external vacuum pumps ie electric or a mechanical pump attached to the rear of the alternator.
anti shudder valves tend ti fill up with dirty diesel engine oil.

hope this helps.

After reading posts in these and other forums months ago about how the throttle plate is actively used while driving to assist with egr and the potential issues regarding the turbo that some have mentioned. i decided not to fit an egr blanking plate.

What i did do recently was fit metal boost pipes and wanted to datalog and see the before and after effect on boost response.
I fitted hot and cold side pipes removing that long u-bend on the hot side.

What i found was that the throttle plate never closed, only briefly at shutdown to prevent engine shake.
Throttle valve power off position is open due to it being spring loaded that way.
It only closes with a voltage applied but remains open when powered off.
One can see this in the TP applied voltage reading and in the TP(%) readings as you turn ignition to off as it closes and then opens again.

So with foot flat or light throttle, hills or descents, hot or cold engine and different ambient temps it remained open.
This got me thinking about the egr assist function that people have mentioned.
So I added this to the datalog and egr valve opens and closed as expected depending on load.

I then fitted a blanking plate and only change is that the egr valve is opened a great deal more.
Probably due to feedback from MAF indicating egr not flowing but no DTC's.
I can see that the MAF reading is a bit higher now than before at idle.
Emissions requirements less stringent here in SA so they don't appear bothered to check if it works correctly.

Interesting that there would be this difference in operation between different markets.

Also explains why the engine braking is so much worse than my previous vehicle.
An Isuzu DMAx 4JH1 motor which still had cable operated throttle plate with a feedback potentiometer to determine fueling requirements. Looked liked they pirated a petrol engines EFI throttle body instead of using a drive by wire system. Was simple and worked though, no extra electronics to control throttle plate for EGR and engine shutdown.

Been a long time since I logged in.
The mods and tuning have been an expensive, drawn-out, frustrating affair. A long story that if anyone cares to know then I'll write the chain of events.
Fortunately this throttle plate issue was resolved, but only after multiple visits and presenting the tuner screenshots to prove what was happening.
It came down to some kind of corruption or incorrect process when downloading the tune file. The factory file was restored. DPF and EGR deletes were then done step by step, followed by the dyno developed tune parameters. Throttle plate now remains open 100%, except on engine OFF when it closes briefly for smooth shutdown.
To correct a few points mentioned above:
The Bosch throttle body is not spring return, it's PWM modulating control with gear reduction.
The EGR valve is similarly PWM control, not vac operated. (EGR cooler bypass is vac open/close however).
Thanks for maintaining the site Stewart. A great wealth of info.
Cheers

Thanks for the update, Peter.

Thanks for the update.

"some kind of corruption or incorrect process when downloading the tune file." Some will say anything, the vehicle would not have started if there was any form of corruption on uploading the vehicle.

Anyway, glad it is sort.