Disco 2 Td5 maf

Hey guys n gals

I'm having peer issues with the disco td5 - it's always been rather gutless but now it's so bad it's hard to get it much past 55!

I've got it on a nanocom evo and it says "air reading" I presume this is for the maf reading? It was zero, I've fitted A brand new maf - still zero

I believe there should be a 5v signal going to it is that right? Is it linked to another sensor that would make it read zero if that was kaput?

Cheers beans

Happen to be watching this earlier . Shows how to test maf for voltage

Oh an excellent video - cheers matey I'll check that tomorrow. I never even thought of checking the fuses!

FYI,

@private penguin

You are not the only one.............

Cheers

Might try that check before ordering the new MAF... as I think my reading was a consistent zero as well?

Starting to think i might have to invest in a nanocom before too long!

vilguy said:

Oh an excellent video - cheers matey I'll check that tomorrow. I never even thought of checking the fuses!

Click to expand...

You better not rely on what that guy sais, he has no clue how the Td5 works cos at min 4.03 he said that the MAF helps with the fuelling strategy .... sorry, i couldn't help myself ... some members here will know why i said that

MAF should read 58 - 62 at idle.

Im interested in this, mainly about the MAF use itself. Mines mapped by TD5inside (AFR mapping) when at maxs revs the MAF doesnt like the higher boost and causes a little stuttering, so its unplugged for the time being. Though I havnt noticed any difference when plugged in and not, bar a high rev stutter.

I know if you unplug the MAF the ECU reverts to default fueling but considering mines mapped the default fueling is different, so plugged in or not it makes no difference? Im I right in thinking this?

Do you have a boost box too by any chance?

sierrafery said:

Do you have a boost box too by any chance?

Click to expand...

Nope, uprated MAP sensor and electronically raised boost limit.

sierrafery said:

You better not rely on what that guy sais, he has no clue how the Td5 works cos at min 4.03 he said that the MAF helps with the fuelling strategy .... sorry, i couldn't help myself ... some members here will know why i said that

Click to expand...

Yes indeed and it doesn't.

bankz5152 said:

Nope, uprated MAP sensor and electronically raised boost limit.

Click to expand...

i presume then that the MAF map should have been addapted to that too and not create problems cos at raised boost the sucction on a std MAF setup can easily exced 680 reading then the ECU cuts the fuelling for turbo overspeed protection, from your signature seing it's '04 Defender i can deduce that it's a 15/16(or beyond)P engine and the EU3 fuelling calculations are based on MAF readings too but unplugging it everything goes on the MAP/IAT input which is altered as to accept higher boost...IMO it's a vicious circle and you need all sensors to work within expected limits to have a smooth run

if you want to know exactly what's going on have a read through this(and associated links about MAP recalibration): http://www.discotd5.com/td5-tuning/airmass ... IMO this guy is the best in this area

Though do the standard MAFs not have a max value they can give? Before they need to be removed or uprated like the MAP sensor? I know Allisport and a few others completely remove the MAF sensor in some highly tuned race trucks.

Cool! Cheers I shall have a read (again) some of their stuff goes straight over my head though!

bankz5152 said:

Though do the standard MAFs not have a max value they can give? Before they need to be removed or uprated like the MAP sensor? I know Allisport and a few others completely remove the MAF sensor in some highly tuned race trucks.

Cool! Cheers I shall have a read (again) some of their stuff goes straight over my head though!

Click to expand...

That is because it is only needed for EGR.

The MAF is only needed for the EGR? My EGR is totally removed, inc the cooler. Just one pipe left

bankz5152 said:

The MAF is only needed for the EGR? My EGR is totally removed, inc the cooler. Just one pipe left

Click to expand...

Be that as it may, that is what it is fitted for it does not at any time dictate fuelling.

bankz5152 said:

Though do the standard MAFs not have a max value they can give? Before they need to be removed or uprated like the MAP sensor? I know Allisport and a few others completely remove the MAF sensor in some highly tuned race trucks.

Cool! Cheers I shall have a read (again) some of their stuff goes straight over my head though!

Click to expand...

The standard MAF gives up to 5V like the MAP and at around 4.7 based on the ECU's ADC(analog digital converter) the value is 680kg/hr, that's the max limit exactly like the overboost and the ECU cuts fuelling so some ''kangaroing'' will occur exactly like on overboost.... that's how the ECU was built to act by those who dont have a clue how the engine works and that's what it does .,.. an electronic system will do what it was programmed to do and the Eu3 version is built as to calculate the IQ based on MAF readings as it's demonstrated in that link i posted... i keep repeating this to mr @wammers who has no clue about applied electronics while it's expert when it comes to the diesel engine's mechanical behaviour and he will reply soon that the engine is throttled by fuel not by air(which i completely agree)

....and we're off.

davidsmith1307 said:

....and we're off.

Click to expand...

Down the rabbit hole we go..........

Cheers

Don't tell me you have a deja-vu guys

sierrafery said:

The standard MAF gives up to 5V like the MAP and at around 4.7 based on the ECU's ADC(analog digital converter) the value is 680kg/hr, that's the max limit exactly like the overboost and the ECU cuts fuelling so some ''kangaroing'' will occur exactly like on overboost.... that's how the ECU was built to act by those who dont have a clue how the engine works and that's what it does .,.. an electronic system will do what it was programmed to do and the Eu3 version is built as to calculate the IQ based on MAF readings as it's demonstrated in that link i posted... i keep repeating this to mr @wammers who has no clue about applied electronics while it's expert when it comes to the diesel engine's mechanical behaviour and he will reply soon that the engine is throttled by fuel not by air

Click to expand...

It is. You don't have a bloody clue. I will say again for the very last time, a stoichiometric air fuel mixture ratio on a diesel engine is only ever approached when EGR is active. It CANNOT be achieved at any other time. They are throttled by fuel, more fuel faster, less fuel slower, air is constant for any given engine speed manifold pressure.