106 magneti marelli ECU

pae

Wrench Pro
Points
61
Location
Uckfield, East Sussex
Let me try and describe this.....

On a 106 1.1 (1994) with Mag marelli ECU there's a hose (white, about 6mm o.d.) coming out of the underside of the ECU (or around that area). It then goes into a small cylindrical box alongside the drivers side suspension turret, and then into another hose (black hard plastic, I think) which goes around the bulkhead and into either the bottom of the throttle body (at the back) or the top of the manifold.

It's not the MAP sensor, I can see that on the bulkhead, and the hose that feeds that.

The hose I'm talking about seems to enter the t.body/manifold about 1-2cm above the MAP hose.

What is it? Can I post pics on here to help?

Phil
 

Freddie

Road Burner
Points
72
Location
Surrey
At a guess it could either be a sensor to test air tempreture in the inlet, an idle control valve, or a throttle position sensor.. I'm trying to think if there would be any other sensors on the t/b plenum, but nothing springs to mind.
 

pae

Wrench Pro
Points
61
Location
Uckfield, East Sussex
Could be. I think I've located the throttle position one towards the front of the t/b, and would have thought inlet air-temp would be a sensor screwed in with wires coming out (rather than a plastic hose). Possibly idle control.... any idea how they work?

I've had a look through Haynes (descriptions and wiring diags) and have located most sensors to the ECU, which is why I'm a bit baffled about this one.

Unless it doesn't even actually go to the ECU, just runs underneath it, but I can't find where it goes if that is the case????

Will have another look...

Phil
 

obi_waynne

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A3 1.4 TFSI 150 COD
Yup - me too - cancelled my night out also. :lol:

Owning a car is a continual voyage of discovery! I suddenly realised that my car almost stops when I push the middle pedal. :shock:

Good luck PAE - and welcome to the site.
 

pae

Wrench Pro
Points
61
Location
Uckfield, East Sussex
Freddie, Waynne - have a sleepless night?

Well, it's amazing what you learn when you look properly. The 'black cylinder' has got wires going to it when you move the rest of the loom out of the way. A-ha, let's have a look at the wiring diagram then. Do you know what it is???? Course you don't.... well it's the charcoal canister hose and solenoid coming in from the drivers side wheelarch and feeding the petrol vapour back into the manifold. Don't pretend you knew that all along, I ain't listening.

You can catch up on your sleep now, sorry about the flight, you wouldn't have enjoyed it :lol:

Charcoal canister questions? bring 'em on, I'm the expert :(

cheers, Phil
 

obi_waynne

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A3 1.4 TFSI 150 COD
Very sleepless night!

Umm Yeah - I Knew that. So charcoal expert - what is the absorbtion rate and charcoal grade.

Only joking - well done sherlock. :lol:
 

Freddie

Road Burner
Points
72
Location
Surrey
I don't understand, the petrol vapour is coming from where? And fed back into the inlet manifold? Sounds dodgy to me! All those unburned particulates and such!
 

obi_waynne

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Location
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A3 1.4 TFSI 150 COD
Quite normal - if it goes back into the engine it gets safely burnt off! Otherwise if vented into the engine bay there is a fire risk.
 

pae

Wrench Pro
Points
61
Location
Uckfield, East Sussex
This is what Mr. Haynes has to say...

"the petrol cap is sealed and petrol vapours that build up whilst the car is parked are vented into a charcoal canister in the front offsied wing. When the engine is hot the solenoid opens and they are purged from the canister into the inlet tract to be burned in normal combustion"

clever eh? If the fuel cap vented to atmosphere I guess you'd have a cloud of petrol vapour around the car, and the environment would shrivel up and die, along with all of us, so we are all saved, thanks to my charcoal canister.

That's enough for todays lesson. I'll go and find something even more obtuse to tax you with tomorrow.

Phil
 

Freddie

Road Burner
Points
72
Location
Surrey
My Dad: ''I don't do 'distructions''

But I'm still a bit miffed as to why the petrol has to vented?

Surely the tank is airtight?

But still sounds clevAR though!
 

obi_waynne

Administrator
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Moderator
Points
1,137
Location
Deal, Kent UK
Car
A3 1.4 TFSI 150 COD
A tank of petrol will on a hotish day result in vapour forming which is incredibly explosive. You can't leave that around the car or it will blow up when you approach it wearing your blue/white shell suit! (Remember them?)
 
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