1m ECU vacuum hose G60 important?

[vagingit.co.uk 0]

How vital to the smooth running of a G60 is the 1m vaccum hose from the throttle body to the ecu?

 

Where mine attaches to the throttle body, it is a bit frayed, thin and crappy, is it worth replacing, and is it available from the dealers still?

[Critical_Mass 10]

Yes, it must be 1 metre long. Not 100% sure why but it must be the correct length.

 

Not sure if the original part is still available sorry.

[nemesis360 0]

Very important, that hose feeds the map sensor which in turn controls the fuel mixture...so yes get it replaced :)

[Jim 2]

Yes - very important that it's in good shape and that it is EXACTLY 1 metre long :)

[16VG60 1]

Vac hose is available by the metre from dealer part number N 020 353 27. It is best to buy 2 metres and then measure the exact length for yourself. The teason for this is some parts guys can cut a little too short and this is no good to you.

[leeeeshad 0]

My VW dealer couldn't find it, I got something similar from someone on here, its 3.2mm id IIRC

[vagingit.co.uk 0]

trip to vw it is then

just measured the one thats on there, and its 80cm long, so definately not right

 

could this vaccum hose be the cause of it feeling flat and hesitant at full throttle? its fine at 3/4 throttle, but when you put your foot down, its quite lethargic after 4k

[Rob_B 0]

can anyone actually explain why it has to be 1m long?

[vagingit.co.uk 0]

no idea to be honest, but vw have just arse raped me on price. And I have to buy 5m of it, but then I need to replace to engines worth, so its nt too bad really

[Jim 2]

Was talking about it with Yandards a few weeks back as I was interested to know why it has to be exactly a metre long. My recollection is hazy but I believe it's something to do with manifold pressure or something and the ECU has hard coded values that will be correct if that pipe is exactly a metre long. If it's not the correct length it means that the values do not correspond with what they should be and it will consequently mess up how the engine runs. Yes, I'm being terribly vague... I'll PM Yandards and ask him to correct me on this ;)

 

vaginigit - dealers are sh!ts for that. They should only charge you for a metre and supply a metre but because they can only buy it in 5m segments and because they know they probably wont sell any more, they pass that loss straight on to you. You should just cut 5 nice segments and resell them on here to make your money back!

[leeeeshad 0]

Iv read its due to the way the air pulses down the pipe, so if it was too short the pulses would be too quick, and if it was long they wuold be too slow.

[Rob_B 0]

I heard it was to do with the lunar cycle

[Yandards 0]

Iv read its due to the way the air pulses down the pipe, so if it was too short the pulses would be too quick, and if it was long they wuold be too slow.

 

Yes this is almost correct.

 

Despite the fact that we assume the air flow in the inlet manifold etc is linear/constant it is not, even the charger pressure is in a series of pumped 'waves' we just see a solid reading on a gauge because the air is being pumped very quickly and the gauge lags.

 

So, much the same as an exhaust system (in which the correct length and bore make a huge difference 1) then the length of hose for the ECU MAP sensor has to be exactly 1 metre to ensure the piezo electric sensor is fed a smooth linear read of the inlet airflow pressure to prevent it from spiking up and down and messing the fuelling up.

 

and that's the reason for a 1 metre long hose, not due to the curvature of the Earth or other such piffle :)

[dannyboy 0]

The ecu MAP sensor is calibrated to the manifold by using basic physics.pressure(vacuum or boost) acting in a cylinder(vacuum hose) on an area(MAP sensor diaphram)

This acting on the diaphram inside the map sensor which has a carefully measured surface area which moves to vary the voltage that the ECU recieves.this voltage adjusts the fuel accordingly

 

From memory i believe 5v reference voltage,ground and signal

The signal voltage varies as the diaphrams moves, 1v on idle to 5v on boost,to put it simply- a variable resistor

 

different size hose diameter or length will change the force acting on the diaphram giving a inaccarate reading resulting in overfuelling or underfuelling

 

its what i can remember at the moment,there is a formula to calculate it but its friday and the pub is calling :clap:

 

yandards is correct with the pulses(thought the digifant had a analog map sensor though?could be wrong :notworthy: )

[Rob_B 0]

Witchcraft. Fact!

[dannyboy 0]

Witchcraft. Fact!

 

:lol:

[laurielaeks 10]

sorry for bumping an old thread but i need to replace my vaccum hose and ive ordered this http://www.deimosaircooled.com/products/engine/ignition/vacuum-hose/113-201-910-a i just want to make sure this will be fit for the job once i cut it down to 1m? thanks

[JonnyG60 10]

Yeah looks fine, correct 3.5mm ID.

[laurielaeks 10]

excellent thanks