Td5 airflow meter

[Harald Hansen]

I've got a Hawkeye diagnostics tool for the Td5, and as the old girl is a bit tired, I had a look at the numbers for the MAF to see if maybe the meter needed replacing (2000 Disco Td5). I took a few readings from a mate's Disco (same year and engine) for comparison:

RPM______My airflow___Mate's airflow

___0_________4.4____________4.4

_800_______~42____________~55

1500______~100___________~120

2000______~140___________~170

3000______~280___________~310

4000______~500_______________

Most of the numbers are approximate. The fault log had a "3030 Air flow high" error stored. I tried to get Google to find me some numbers to compare with, but came up empty handed. Any ideas if these numbers are within normal range?

[Ally V8]

Your readings are a bit low,from memory they should be 55-60Kg/hr at idle,330Kg at 3000rpm engine hot all loads off.They do seem to tail off slowly and owners do not realise the power dropping off.Some advocate cleaning them,I rarely have found this to work,nor do cheap aftermarket replacements.If it runs better disconnected then its a sure sign its reading low.If the ecu does not see a high enough reading it simply wont put enough fuel to it to make power.

[Harald Hansen]

Thanks for the feedback, Ally. On that note, I cleaned the AFM out with both brake and electronics cleaner, and left it overnight to dry out. I got a new set of numbers this morning:

RPM______New airflow

_800_______~64

1500______~150

2000______~220

3000______~420

So quite a bit higher. I had a test drive, but it was difficult to tell if it translated into increased power, but I'll keep an eye on the MPGs the next weeks.

[M&S]

Thanks for the feedback, Ally. On that note, I cleaned the AFM out with both brake and electronics cleaner, and left it overnight to dry out. I got a new set of numbers this morning:

RPM______New airflow

_800_______~64

1500______~150

2000______~220

3000______~420

So quite a bit higher. I had a test drive, but it was difficult to tell if it translated into increased power, but I'll keep an eye on the MPGs the next weeks.

Very interseting, thanks for posting.

[Ben_J85JTY]

Very interseting, thanks for posting.

I found their to be a difference in output after cleaning one with electical contact cleaner. Didn't last long, but worth it while I waited for the new one.

[M&S]

I replaced one last year, as it was faulty. Be interested to know what the readings are in another 1000, the 6000 miles?

[Harald Hansen]

I'll try to remember and update in a while. I'm keeping an eye on my mileage anyway, as it has been in the 14-15 l/100 km range for a while now. For the record, the breathing for this engine is completely stock. No aftermarket filters, no raised air intake or anything like that.