MAF readings D2 V8

[jiri_j]

Anyone can remember what should be readings of a perfectly working MAF at idle on D2 V8? My measurements show around 5g/s. Is this what I should expect?

And also: is there anyone in Canberra who would let me try his/her working MAF before I go and purchase a new one? Just for a few minutes only :angel:

Thank you!
J

[justinc]

26 to 30 Kg/hr is what I have seen IIRC. That is almost twice 5g/s. Sounds like you have a low output there.

JC

[jiri_j]

I have found on another forum 30 kg/hr when idling. Not sure if it is for V8 or TD5 though. I searched internet for a while but couldn't find anything. Is there someone else who could confirm 30 kg/hr MAF reading at idle? Thank you all! J

[justinc]

I have found on another forum 30 kg/hr when idling. Not sure if it is for V8 or TD5 though. I searched internet for a while but couldn't find anything. Is there someone else who could confirm 30 kg/hr MAF reading at idle? Thank you all! J

You can bet that is for a V8. A Td5 should be no less than 50 at idle...

JC

[Pedro_The_Swift]

Be wary of the small radiator return line when undoing those clips---:eek:

[phuma]

I think it is important to quote the RPM at which you were measuring when you say "idling". I see you've also posted on landroversonly.com that:
- 18kg/hr @ 660 RPM
- 21kg/hr @ 700 RPM
I would assume this is a manual then - the autos idle a bit higher; I think at around 730 RPM? Therefore if somebody else says 24kg/hr when idling they may be referring to an auto.

My Disco 2 V8 is:
- 18kg/hr @ 640 RPM
- 22kg/hr @ 750 RPM
- 58kg/hr @ 2000 RPM

Does that look familiar / ok?

[jiri_j]

Yes, in my case it was manual and idle was at 660rpm. BTW I checked RAVE and could find nothing regarding idle speed for manual and auto. It is just 660 +/- 50 rpm for a V8 engine...

My readings are:

idle (660 rpm :-) 18 Kg/hr
2500 rpm 59 Kg/hr

RAVE - Range rover V8:

idle 20+/-3 Kg/hr
2500 rpm 60+/-3 Kg/hr

Hope this helps. regards Jiri

[phuma]

So very similar to mine then... so either ours' are both stuffed, or they are ok! At least they look ok around 2000 RPM, which is probably a good sign. I have asked for another opinion about the kg/hr.

Did you resolve your misfire issues?

[clubagreenie]

How are these measured? I have a new (<2mth) Maf on D2 auto (new engine and auto) so I can give some 1/2 decent readings if you tell me how.

[phuma]

clubagreenie - you've got to find somebody with a diagnostic device to do this. I.e. at an independent mechanic, or maybe a friend with something like a "hawkeye" or newer "nanocom" readers. Thanks for the offer!

[clubagreenie]

So it's a reading of a voltage based input into the ECU?

[phuma]

Yes - but you have to get the reading using a diagnostic scanner. You can also try get the voltage reading I suppose, but I have not found a "clean" place that I could get that without using needles into the wires. Will think about that a bit...

[jiri_j]

Yes - but you have to get the reading using a diagnostic scanner. You can also try get the voltage reading I suppose, but I have not found a "clean" place that I could get that without using needles into the wires. Will think about that a bit...


You can unplug the little wires going into the ECU, this is #23 (signal) and #9 (earth) of the C0636 ECU connector. I used tiny wires, made a contact to the signal wires, plugged them back into the C0636 connector and then to the ECU. You can use a voltmeter or osciloscope to measure the signal then.

In my case I used an OBD tool though.

The readings I got are within spec, so I assume that the MAF is working perfectly. I have also a stuffed MAF and this shows the same values at idle but 10% less at 2500rpm. The long term fuel trim was corrected to 10% as well with this MAF which makes sense.

Regarding backfiring: I suspect IAC valve, want to try a working one and see. I will keep you informed. Cheers J

[rusty05]

You can unplug the little wires going into the ECU, this is #23 (signal) and #9 (earth) of the C0636 ECU connector. I used tiny wires, made a contact to the signal wires, plugged them back into the C0636 connector and then to the ECU. You can use a voltmeter or osciloscope to measure the signal then.

In my case I used an OBD tool though.

The readings I got are within spec, so I assume that the MAF is working perfectly. I have also a stuffed MAF and this shows the same values at idle but 10% less at 2500rpm. The long term fuel trim was corrected to 10% as well with this MAF which makes sense.

Regarding backfiring: I suspect IAC valve, want to try a working one and see. I will keep you informed. Cheers J

So I have a scan gauge, am I able to configure some custom data collections to gather this info....similiar to how you can measure the O2 sensors.

Id like to know how to get these figures if you dont have a nanocom
So I can see you can see u measure the voltage...then I assume there must be a lookup table somewhere to convert voltage to kg/hr etc.

[Pedro_The_Swift]

is the bottom right what you are after?

[trout1105]

I have a scangauge unit I bought from 4wdsupercheap plugged into my OBD2 port and it gives me a MAF reading [thumbsupbig]

[PhilipA]

BUT BUT!
It doesn't matter much once the car is warm.

The O2 sensors are the main mixture setting method that Motronic or really any O2 sensor car will use, either up to 50% or sometimes more throttle.
The TPS will provide an early enrichment signal on acceleration , but for normal driving and idling the o2 sensors are the primary mixture setter.
If the car goes well at full bore and has good drivability at less than half throttle , you should not worry too much about the MAF reading.
The MAF sets the mixture before the car reaches operating temperature when the o2 sensors take over. If you have a problem with cold running then blame the MAF
Regards Philip A

[rusty05]

I have a scangauge unit I bought from 4wdsupercheap plugged into my OBD2 port and it gives me a MAF reading [thumbsupbig]

Ill check when the car gets back...
I recall it has a MAP reqading, which i think the manual said was for diesel.

My scan gauge is old... Ill try to find the manual and check it.
thanks trout.

[rusty05]

is the bottom right what you are after?

yep, is that an obd app on your phone?

[Pedro_The_Swift]

yep,, Torque. there are a few around,,
great use for old smart phones[wink11]

[rusty05]

I have a scangauge unit I bought from 4wdsupercheap plugged into my OBD2 port and it gives me a MAF reading [thumbsupbig]

Bugger my scangauge doesn't have MAF, has MAP but MAP shows nothing.