P38A 2.5TD engine torque maps

Hi all,

In this link are the ECU maps with torque values for the M51 engine as fitted to the Vauxhall Omega: Inside the 2.5TD ECU.

Q: does anyone have the equivalent values for the M51 engine as fitted to the P38A?

Cheers,

J

Look on the PSI site they give before and after torque curves for the P38.

wammers said:

Look on the PSI site they give before and after torque curves for the P38.

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In case you did not read the link Tony, below is the detail of how the MAF works, it's one of the pieces of info I lost when my computer went tits up:-

[FONT=Arial, sans-serif]Since boost is controlled mechanically, the only thing the ECU controls is when and how much fuel is delivered, and in simplified terms fuel equals torque in a diesel engine.
The fuel injection quantity (or IQ) is based on the driver pedal input, then limited by the MAF to prevent excessive smoke and also limited by a torque limiter to prevent mechanical failure.[/FONT]


[FONT=Arial, sans-serif]The smoke limiter map limits injected IQ based on mass air flow read from the MAF. If we did not have this map, the engine would be flooded every time the driver gave the car a lot of throttle, because there would not be enough air in the engine to combust the fuel.
Why is it called smoke limiter? Because diesel starts to smoke quite a bit when it is running rich, so this map limits smoke among other things.[/FONT]
[FONT=Arial, sans-serif][/FONT]
[FONT=Arial, sans-serif]Not that I expect you to believe it!

[/FONT]

Datatek said:

In case you did not read the link Tony, below is the detail of how the MAF works, it's one of the pieces of info I lost when my computer went tits up:-

[FONT=Arial, sans-serif]Since boost is controlled mechanically, the only thing the ECU controls is when and how much fuel is delivered, and in simplified terms fuel equals torque in a diesel engine.
The fuel injection quantity (or IQ) is based on the driver pedal input, then limited by the MAF to prevent excessive smoke and also limited by a torque limiter to prevent mechanical failure.[/FONT]


[FONT=Arial, sans-serif]The smoke limiter map limits injected IQ based on mass air flow read from the MAF. If we did not have this map, the engine would be flooded every time the driver gave the car a lot of throttle, because there would not be enough air in the engine to combust the fuel.
Why is it called smoke limiter? Because diesel starts to smoke quite a bit when it is running rich, so this map limits smoke among other things.[/FONT]
[FONT=Arial, sans-serif][/FONT]
[FONT=Arial, sans-serif]Not that I expect you to believe it!

[/FONT]

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No because it's a load of bollocks. How does the none MAF engine control smoke?

wammers said:

No because it's a load of bollocks. How does the none MAF engine control smoke?

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It doesn't on the ones I've seen, the smoke when booted.
When you can decode engine maps come back with a sensible answer.

Datatek said:

It doesn't on the ones I've seen, the smoke when booted.
When you can decode engine maps come back with a sensible answer.

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Keith don't talk daft it is getting annoying now, explain to me how a none EGR none MAF diesel engine works without smoking please, if you know, which i doubt. The MAF measures the airflow, so the ECU knows how much exhaust gas is being ingested by the engine at any particular engine speed whilst EGR is in operation. The ECU then opens or closes the EGR for optimum effect. More air flow less exhaust gas, less airflow more exhaust gas. The ECU knows how much air is present at any engine speed or manifold pressure from it's Map. The engine is throttled by fuel, quantity derived from the fuel Map, a set amount, derived from other sensor readings (engine temp, fuel temp, inlet air temp). Inlet air temp being a low preset within the ECU to ensure EGR operation, within a parameter controlled by the anti smoke Map for any requested engine RPM load, the anti smoke Map stops the ECU from giving more fuel than the maximum allowed for that particular engine speed/throttle request/ engine load to prevent smoke. Just as the none EGR engine does. ANY reduction in required fuel quantity at ANY requested RPM will cause the engine to slow down. No EGR is operational on acceleration so the airflow through the MAF is irrelevant and the engine operates just as the none EGR engine would. Only when EGR is in operation do the MAF readings have any consequence. The MAF does not control fuelling.

This is, as you say, getting boring, MAF is used to fine tune the fueling.
Plenty of threads about it on other sites where the M51 engine is used, also confirmed in the last edition of RAVE correcting the error in earlier versions which only mentioned EGR.
As you say I know feck all about it, that's why I did a lot of research when contemplating a P38, there is little info on Range Rover sites but plenty elsewhere including VAG sites where the same basic EDC setup is or was used on some cars.
I have the greatest respect for your knowledge of the mechanics of FIP's or EAS valve blocks etc, but you have been wrong before, remember our difference of opinion about the centre diff and VCU?
I will continue to present the alternative view point so people can make up there own minds and not discount the MAF when problems arise.

Datatek said:

This is, as you say, getting boring, MAF is used to fine tune the fueling.
Plenty of threads about it on other sites where the M51 engine is used, also confirmed in the last edition of RAVE correcting the error in earlier versions which only mentioned EGR.
As you say I know feck all about it, that's why I did a lot of research when contemplating a P38, there is little info on Range Rover sites but plenty elsewhere including VAG sites where the same basic EDC setup is or was used on some cars.
I have the greatest respect for your knowledge of the mechanics of FIP's or EAS valve blocks etc, but you have been wrong before, remember our difference of opinion about the centre diff and VCU?
I will continue to present the alternative view point so people can make up there own minds and not discount the MAF when problems arise.

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It is there to fine tune yes but not the fuelling, over which it has no effect, it fine tunes the EGR nothing more. It controls the amount of exhaust gas entering the engine to reduce the oxygen content of the charge air to reduce heat and therefore the manufacture of NOX. That is what it is there for. Diesels are fuel dependent for RPM control, it is fuel that controls RPM NOT air charge as in a petrol engine. Any reduction of fuel supply at any given RPM will cause the engine to lose power. EDC gives a much finer control of fuelling over the RPM range than a wholly mechanical pump can. EDC Maps emulate the analog controls of a mechanical pump but do it to a far finer degree. It is a simple matter to increase engine power on a mechanical pump by increasing the fuel at the start point, but doing that will increase tick over RPM because fuel controls RPM, that would need adjusting back to normal. But as the throttle is opened, more fuel will be injected in a linear fashion throughout the rev range of the engine, increasing the power output at any particular point. Over do this and the engine will smoke. This is exactly what a tuning chip does on an EDC pump but it is done electronically and not mechanically. The anti smoke Map on the EDC prevents over fuelling through the RPM range. It ensures that no more than a set amount of fuel, within a certain quantity range is injected at any particular point relative to the engine speed, load and throttle demand. This prevents smoke. This is true of the none EGR engine and the EGR engine. There is no difference at all in the way fuelling is controlled engine to engine. But on the EGR engine a MAF has been added to enable the ECU to control the EGR valve to cut NOX and whilst doing that fine control it avoid as far as possible soot production. If for instance the EGR valve was open on acceleration the engine would smoke like a WWII destroyer because there would not be enough oxygen in the air charge within the cylinder to burn the injected fuel. It would not produce NOX but it would produce smoke and soot. A badly controlled EGR is a prolific creator of soot, that is what the MAF is there to prevent whilst EGR is in operation reducing NOX production. A finer control of EGR to stop soot deposits. Those are the facts believe them or not as the case maybe.

Ah well, you seem to be in a minority of one one this.

op2:

Saint.V8 said:

op2:

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will the handbags be out soon saint im running out of popcorn

Datatek said:

Ah well, you seem to be in a minority of one one this.

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Keith believe what you want to. You are wrong.

Here we are In Black and white smoke fueling and egr now stop arguing

MAF SENSOR PROBLEMS.

Grit Valve said:

Here we are In Black and white smoke fueling and egr now stop arguing

MAF SENSOR PROBLEMS.

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Different injection system Grit. Not the same thing.

wammers said:

Different injection system Grit. Not the same thing.

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You asked how the non egr did it,with the sensor in the air manifold .

The non mafs still have a sensor somewhere.

But the princible is the same for most electronic ecu cars how else would it know how to fuel apart from rpm signals it needs to know what comming in combined with revs ect ect from various sensors .

Grit Valve said:

You asked how the non egr did it,with the sensor in the air manifold .

The non mafs still have a sensor somewhere.

But the princible is the same for most electronic ecu cars how else would it know how to fuel apart from rpm signals it needs to know what comming in combined with revs ect ect from various sensors .

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I know how the engine and EDC work Grit, i asked Keith if he did.

My old van didn't have any electronics to control fueling. Instead it went for an all mechanical system. The MAF gave more accurate fueling, but also added an unneeded complication, all in the name of economy.

Screw electronics, pullies and levers FTW. No T/C, no ABS, no PAS, no nonsense.

Grit Valve said:

You asked how the non egr did it,with the sensor in the air manifold .

The non mafs still have a sensor somewhere.

But the princible is the same for most electronic ecu cars how else would it know how to fuel apart from rpm signals it needs to know what comming in combined with revs ect ect from various sensors .

Click to expand...

The none EGR engine knows whats coming in at any given RPM/manifold pressure from it's ECU Map. Basically if the max engine speed was say 4000 RPM and 50% throttle was requested the engine would be fuelled for 2000 RPM, the quantity derived from it's fuel Map subject to readings from other sensors fuel temp, engine temp, inlet air temp, manifold pressure. And of course the load being applied to it. The maximum quantity controlled by the Smoke/Torque Map. The EGR engine is no different other than the inlet air temp sensor is not used. Instead a low preset is used to ensure the EGR operation. So the ECU thinks all the air coming in is cold and dense. The MAF is used as described earlier in the thread.

Grit Valve said:

Here we are In Black and white smoke fueling and egr now stop arguing

MAF SENSOR PROBLEMS.

Click to expand...

I doesn't matter how much evidence you provide to the contrary, Wammers will not accept it. Even the final version of RAVE states that the MAF is used for fuelling.
I came to this with no knowledge and did a lot of research to find out how it all worked, so I'm happy that I have the right conclusion, I have provided info from other sites to support my position, Wammers on the other hand just keeps repeating the same thing over and over with no independant supporting evidence.
Think about it, if the EDC can read the MAF, why would you not use it to trim fueling? It allows fuelling compensation for engine wear, altitude etc, it would be illogical to fit and expensive component, re-write the EDC software to read the values and then ignore them for the most part. With the EGR blocked, according to Wammers statements, the MAF should have no effect and therefore it should be possible to disable the hot wire part leaving just the inlet air temperature sensor in place. Try it, you will find that the engine does not run as well, although unlike a petrol it still runs well enough as it relies on the default maps.
Even when a guy smart enough to decode the fuelling maps and modify them states that the MAF is used to trim fuelling, Wammers will not have it.
I don't much care either way, but I think both versions should be presented so that peeps can make up their own minds and not be led in one fixed direction

Subject change lol
is it normal to give a puff of smoke on start up?
Couldent tell you the exact colour cos its usualy dark when I go to work but I would say more gray/blue (oil)than black but I only just catch a glimps in the reverce lights and it stops within the time it takes to get round to the back of the car
only just noticed it but could have been doing it a while
couldnt tell you if its useing oil cos its a rr and most of it comes out the bottom
but hey at least I dont need to do oil changes cos I do a progressive oil change constantly
(Lol only joking every 8k religiously)