Disco 300tdi air flow meter

Tim M · 07 May 2008, 19:00

Can anyone tell me where to find the airflow meter on my 300tdi auto? I've posted this on landyzone but no-one responded. A photo would be handy too!

jwalker · 08 May 2008, 00:01

Are you sure it exists?

Tim M · 08 May 2008, 09:20

Well, Landrover say it does. I had a look on Landyzone and there are references to an "air flow meter" so I'm assuming there is one.

jwalker · 08 May 2008, 09:35

Tim, when you find out, you can tell me where it is.

A petrol v8 will have an air flow meter. The the ECU uses that info to calculate how much fuel to inject.

Tim M · 08 May 2008, 09:40

So are you saying a 300tdi won't have one? That's interesting - I searched on ebay for an air flow meter to see what it looks like and they are all for petrol discos.

Begs the question why Landrover say I need a new one at £650.....

jwalker · 08 May 2008, 09:41

Quote:

Originally Posted by Tim M

Begs the question why Landrover say I need a new one at £650.....

Tim M · 08 May 2008, 09:49

Point taken.

Tim M · 08 May 2008, 09:58

What is this bit?

jwalker · 08 May 2008, 10:15

Dunno. It looks like an air flow meter.

Mine doesn't have one of them! Am I missing out on something?

Tim M · 08 May 2008, 10:17

If this is an air flow meter, what is likely to be wrong with it? Is it worth taking part to spot anything obvious?

jwalker · 08 May 2008, 10:26

Quote:

Originally Posted by Tim M

If this is any air flow meter, what is likely to be wrong with it? Is it worth taking part to spot anything obvious?

I dunno anything about that one. I'm familiar with the Lucas type for petrol engines. There were different variants of these. Some used a hot wire which changed resistance depending on the cooling effect of the air flow. It was essential to have an effective air filter to prevent debris damaging the wire. The wire could be seen across the passage when looking through the unit. The electronics was a small board which used surface resistors. The unit was calibrated by scraping away a small portion of the resistor.
I'll have a look in my Disco manual to see what info I can find for you.

jwalker · 08 May 2008, 10:50

Ok Tim, it seems you have one of the 300tdi cars with Electronic Diesel Control (EDC). The unit is not referred to as an air flow meter, it is called an air flow sensor. There is no indication in my manual of its function or its internals.

If I can suss anything more, I'll let you know.

codprawn · 08 May 2008, 12:27

Late 300tdi Autos had EDC fitted which includes fly by wire throttle - airflow meter and all the other stuff.

What problems are you having? Sometimes air can leak into the airflow sensor or more often the throttle potentiometer plays up.

Tim M · 08 May 2008, 23:10

It all goes back to when I had my starter motor trouble (see other thread!).

Having replaced the start motor, the car ran really rough. Has been like that ever since. When i try to start it from cold, it will rev a bit for maybe half a second, then drop back down. I then have to give it some revs to prevent it from stalling. I keep it in an underground carpark; I drive out of my space, around the corner, probably about 20 seconds to the ramp that takes me outside. Often it will stall going up the ramp - really doesn't like any sort of stress when its cold. The only solution seems to be to keep it reving quite high, which involves keeping one foot on the brake to slow it down and the other on the revs. Not ideal! The check engine light is always on as well.

The only other thing is that for some reason it wont start (or even turn over) once the ignition has put switched on more than once. For example, I might start it, run it for a minute, it will stall, but then I have to turn to the key all the way to off before I can restart it. I could swear before I could just start it again from where the key was.