How to completely get rid of MAF on de-EGR'd TD5

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Originally Posted by Dougal

You need to understand these limiters and how they work with each input before you can claim any sort of improvement with modified signal behaviour.

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1. ok, can you give me a link with what to download please?


2. i reformulate that this mod is an alternative to a bad MAF for those who dont want to spend on it... it never was my intention to claim it as an improvement


3. i'll learn as much as possible cos it's a kind of hobby to me but what i cant understand is that limiters or not on inputs as long as the output to injectors is the same where is the gist of it? ... so those limiters will do what to keep the injector output steady but modify the EGR output more on MAF input variations? ... in the end the ECM is an electronic microprocessor/controller like a kind of the engine's ''brain'' isn't it? ....so those limiters within the ECU how can they ''impose'' e.g rpm limitation? ... not through the output to injectors? ... and if they do i presume this woukd show on that output signal's waveform or amplitude... as it happens very visible on the EGR output... as i said in a previous thread i made these measurements on the running car too with the same result(only the waveform was a bit different due to the solenoid's load)


in a nutshell: is the engine behaviour (rpm, torque, smoke, etc) managed through the output from ECM to injectors or not? that's what i keep asking simple as for a limited electronist brain:)

This is probably the best debate i've ever read.

I'm not an engineer and don't claim to have exclusive knowledge of any Landrover ECM. I am however an electronics Technican with experience in avionics, auto electrics, only a pre-apprenticeship in automotive mechanics. The business behind where i work tests and repairs ECM's and ECU's and uses the equipment you are referring to for your testing and they have shown me some of their testing. I also work with the Danish on a day to day basis and need to decipher what can most accurately be be described as EURO-ENGLISH. Sierrafery I have to say your English for explaining technical information is brilliant, i knew exactly what 30.000 meant. :)

I'd like to weigh in and ask for some clarification on some posts so far.

Sierrafery - You mentioned in your opinion the MAF should be called simply an Air Flow Sensor. As you are not confident it measures Mass of air. I've thought of a scenario i'd like someone to explain.

If you have a constant air flow and every other parameter is the same for this example BUT you change the temp of the air: surely the MASS of the air changes as the colder the air is the more particles of air will fit into the confined space hence the mass of the air increases. What the ECM uses the output from the MAF for is a different discussion.

Dougal mentioned:
"Connecting ECU MAF input to TPS means at full pedal it thinks it is getting full airflow.
Yet in reality full airflow only happens at full boost and max rpm.

Apply full throttle at 1000rpm and your fooled ECU thinks your engine has airflow potentially in excess of that seen at 4000rpm."

I cannot convince myself, yet, from reading what Sierrafery has written so far that this statement is invalid.

Also mentioned the injector pulses are not changing during your testing. To change mixture ratios is it possible the TD5 changes valve timing to achieve different air fuel ratios rather than changing the injector pulses?

Could you please explain why the 3 above mentioned do not contribute to the ECM of the TD5.

Please understand i'm not trying to discredit you. I'm simply asking questions for further clarification. Who knows it might even help clarify things for Dougal and yourself. Possibly others.

Hi Jazzman, i've already accepted that my statement about air flow was wrong as it was explained clearely by Dougal from the thermodinamic point of view(and as thermodinamics i've learned only in highschool 30 or more years ago my knowlwdge was limited).

the gist of this debate IMO has begun cos it appears from my first post as this is a kind of tuning mod which wasnt my intention i just wanted to shpw an alternative for a faulty MAF... i admit that my first post was not very well written and from what we discussed here i wanted to make some corrections already but couldnt reedit.

if you are asking me about the timing i'm not the man to ask that... all my theory was based on the description from RAVE(Td5 engine management) about MAF's purpose and the simple presumption from pure electronic point of view that if the MAF input doesnt alter much the output to injectors but affects more the output to EGR resulted from my tests too it's signal can be emulated with the TPS signal as it's also a 0 - 5V analogue signal and it will meet the ECM's "expectations" for that... which was also demonstrated by the long drive test of mine cos there were no faults logged with this mod

meanwhile i've got inputs from other guys too that in reality is not quite so and there are cases when it works well(like in my case too) and other cases when it doesnt

i'm perfectly aware that an engine can't be watched exclusively from electronic point of view but all my theory was based on the oscilloscopical measurement of the output

i've been reading tones of articles on the web about MAF since this debate started and i'm still not smarter:(

so from my point of view that was all and the only thing remained unclear for me is that RAVE is inaccurate about that or not

I can't believe this thread is 13 pages long and still no manual EGT readings have been produced.

Better yet EGT values while towing a heavy trailer up a steep hill with foot flat to the floor.

The fact that some on here without EGT have gone out and tried it is I suppose the same reason people still buy hiclones???

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Originally Posted by isuzurover

I can't believe this thread is 13 pages long and still no manual EGT readings have been produced.

Better yet EGT values while towing a heavy trailer up a steep hill with foot flat to the floor.

The fact that some on here without EGT have gone out and tried it is I suppose the same reason people still buy hiclones???

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Is not the first td5 tuning thread with lots of hot air and no egt measurements.

Never heard back on the other one.

according to ebay the gauge will get to me from Belgium thursday so after that i'll go to my mechanic and fit it, if you'll check european forums you'll see that nobody speaks about EGT there...i asked around to see if somebody has it or not and didnt even get an answer:(

Just remember to place it before the turbo not after.
There is a nice cast spot on the manifold just before the turbo which is ideal.
Regards Philip A

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Originally Posted by sierrafery

... if you'll check european forums you'll see that nobody speaks about EGT there....

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I don't know which EU tuning forums you are talking about, but if I search "Auspuff Temperatur" I get heaps of threads on German tuning websites.

i meant land rover forums where i'm member not tuning sites

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Originally Posted by sierrafery

i meant land rover forums where i'm member not tuning sites

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Once again, I am not sure where you are looking, because wherever I look on EU landrover forums, (one seems to be south african, but you get the point...) I find Td5 EGT threads...

Abgastemperatur Td5 !??!

EGT Gauge / Multi-gauge for TD5 - Defender Forum - LR4x4 - The Land Rover Forum

[ame]http://www.lrfaq.org/Series/publications/images/ExhaustGasTemperatureMonitor.pdf[/ame]