Seems to run ok but no difference with MAF disconnected?!

[RoverSevenFive]

Hello, Am new owner of 2002 manual 2.0 diesel. I've noticed that disconnecting the MAF doesn't make any noticeable difference. I don't think the car is driving badly; starts and idles fine, revs through ok with no hesitation or stuttering. Pulls 5th on motorway no problem. Not hugely fast but it's the first one I've ever driven so nothing to compare and would be only the 113bhp I suppose. Does a dead MAF put the car in a perfectly driveable but lower power mode? Or is it a subtle difference when disconnected that I haven't noticed?
Thanks!

[T-Cut]

The standard test for a failed MAF is to unplug it. If that makes no difference to the running you need a new one. A bad MAF can make the car run worse than without it. A T4 check would be worthwhile if you have one near you. I believe Pierburg MAFs are recommended.

TC

[HarryM1BYT]

The standard test for a failed MAF is to unplug it. If that makes no difference to the running you need a new one. A bad MAF can make the car run worse than without it. A T4 check would be worthwhile if you have one near you. I believe Pierburg MAFs are recommended.

TC

I think you meant to say - if it makes a difference, an improvement, you need a new one.

A slightly poor MAF using the above test, might not show. The best test is a T4 check, or check the voltage output. I (or someone else) documented the values to expect, at various engine revs.

[RoverSevenFive]

Thanks for that. Makes sense to check that it is the MAF itself and not whatever drives it so being able to 'check the voltage output' sounds good. But when I put that in the forum search it only returns this thread! Can you point me to some detail please?

[HarryM1BYT]

Thanks for that. Makes sense to check that it is the MAF itself and not whatever drives it so being able to 'check the voltage output' sounds good. But when I put that in the forum search it only returns this thread! Can you point me to some detail please?

Sorry, my mistake - I thought I had documented voltages, in fact I had translated g/s into mg/st and lb/min in a MAF thread. I was using a basic diagnostic unit and struggling trying to relate its readings, to the MAF values used by T4.

That thread is here...

https://www.the75andztclub.co.uk/forum/showthread.php?t=195871

There will be a voltage output, which could be translated, but I have not seen any..

[Mike Trident]

you know when the maf is faulty when you pull out onto a roundabout and believe you are going to die!

A good one makes a world of difference off the mark.

[Avulon]

you know when the maf is faulty when you pull out onto a roundabout and believe you are going to die!

A good one makes a world of difference off the mark.
:wot:

If you don't have this with it connected and no noticeable improvement disconnecting it then it's fine: re-connect it. Disconnecting it results in default values being used (which are fairly sensible) so not much difference between connected and unconnected on an average day. (when it's working right).

[grivas]

The standard test for a failed MAF is to unplug it. If that makes no difference to the running you need a new one. A bad MAF can make the car run worse than without it. A T4 check would be worthwhile if you have one near you. I believe Pierburg MAFs are recommended.

TC

You will need a digimafam to use a Pierburg MAF as it will not work with out it.!

[RoverSevenFive]

Thanks everybody, it does seem to be ok so I've left it plugged in. After a week of leisurely driving I am tempted by a Ronbox & Pierburg MAF though; 113bhp isn't a lot for such a 'well built' machine. Hmm...

[Mike Trident]

Personally I would use the correct Bosch MAF. I have seen the fueling on a pierburg MAF on a T4. It's not perfect by any means.

[lesron]

I have auto that's just failed on black smoke poor emissions 114bhp now their not quick , removed plug from maf massive difference to amount of black smoke and performance ( to a point )sure needs attention to one or more injector
Now my manual saloon 135 bhp is like a rocket in comparison and no excessive smoke , will eventually have a 160 remap for auto when it's running correctly

[Avulon]

Thanks everybody, it does seem to be ok so I've left it plugged in. After a week of leisurely driving I am tempted by a Ronbox & Pierburg MAF though; 113bhp isn't a lot for such a 'well built' machine. Hmm...

Or save a little money and just get a 160 remap......:getmecoat:

[Mike Trident]

160 remap and one of these and you are good to go!

http://www.ebay.co.uk/itm/381351136629?ul_noapp=true

[HarryM1BYT]

160 remap and one of these and you are good to go!

http://www.ebay.co.uk/itm/381351136629?ul_noapp=true

Just to repeat....

Their are lots of fake Bosch MAF sensors around and lots of genuine, but cheaper Bosch sensors, remarked up as the correct part for the 75 or sold as compatible. The fakes are very good indeed, except they don't work to spec., possibly worse than using no MAF at all. There could be a good reason why these are so cheap.

Members and T4 owners have done a considerable amount of research on replacement MAF sensors and....

There is only one certain source for a genuine and correct Bosch MAF and that is the MAFshop. You can buy the genuine Rover part, in its 75 air duct and pay a premium for it, with full guarantee, or buy the same item in a BMW duct, remove the insert and transfer it into your Rover's air duct, save a considerable sum, but lose out on the guarantee. The difference might be marginal, even not noticeable by the average owner, but a T4 will easily show the difference in performance of genuine correct part, versus the rest.

Best read this before investing in a MAF - https://www.the75andztclub.co.uk/forum/showthread.php?t=195871

[clf]

Just to repeat....

Their are lots of fake Bosch MAF sensors around and lots of genuine, but cheaper Bosch sensors, remarked up as the correct part for the 75 or sold as compatible. The fakes are very good indeed, except they don't work to spec., possibly worse than using no MAF at all. There could be a good reason why these are so cheap.

There is only one certain source for a genuine and correct Bosch MAF and that is the MAFshop. You can buy the genuine Rover part, in its 75 air duct and pay a premium for it, with full guarantee, or buy the same item in a BMW duct, remove the insert and transfer it into your Rover's air duct, save a considerable sum, but lose out on the guarantee.

Best read this before investing in a MAF - https://www.the75andztclub.co.uk/forum/showthread.php?t=195871What mike should have added, is that maf is suited to our cars, and from others reporting is genuine. However the housing is for various BMW models, and the insert needs to be removed and swapped over. I have a table at home via Bosch, that states the insert is correct.

Sent from my SM-A310F using Tapatalk

[HarryM1BYT]

Sorry, my mistake - I thought I had documented voltages, in fact I had translated g/s into mg/st and lb/min in a MAF thread. I was using a basic diagnostic unit and struggling trying to relate its readings, to the MAF values used by T4.

That thread is here...

https://www.the75andztclub.co.uk/forum/showthread.php?t=195871

There will be a voltage output, which could be translated, but I have not seen any..

And a correction of a correction, sorry again :duh: - Yes we did produce some voltage readings further down the thread. The voltage values are not what I would describe as precise, just measurements taken from one new MAF unit, installed specially for the test.

[HarryM1BYT]

What mike should have added, is that maf is suited to our cars, and from others reporting is genuine. However the housing is for various BMW models, and the insert needs to be removed and swapped over. I have a table at home via Bosch, that states the insert is correct.

Sent from my SM-A310F using Tapatalk

Thanks..

The price is about the same as that of the MAFshop for the BMW version, where the insert needs to be swapped over to the Rover one. In that case it could well be the genuine insert.

Various BMW's use the 2L diesel in several guises, but with a MAF insert common to all, but a different housing. BMW and other manufacturers used their clout to get the cost of the Bosch MAF's reduced to more sensible levels. Rover being no more, we were left paying the full original cost for our version of the MAF, in a Rover housing.

Same insert, similar housing, but have to pay considerably more.

[Mike Trident]

QI should really have said that the one I provided a link to is the correct insert for our Rovers. I bought one of these and my car has been on big Russ' s T4 a couple of times. (He lives about 2 miles from me). First time he showed me that the fuelling was off a bit with the pierburg. Later it had the 160 remap and a Bosch maf fitted and it runs like a dream now.
Yes, you do loose the warranty as soon as you remove it from the housing.

[clf]

And a correction of a correction, sorry again :duh: - Yes we did produce some voltage readings further down the thread. The voltage values are not what I would describe as precise, just measurements taken from one new MAF unit, installed specially for the test.

I finally found it! There is a Bosch comparison table, whilst it doesnt give the insert numbers it does give a 'type formula' which I am guessing refers to make up of the wire itself. :shrug: LINK (https://www.bosch-automotive-catalog.com/en_GB/vehicle-search) is clunky to use, but enter the car info, then scroll to air sensors, and click the drop down box on the right 'add to comparison' then click the play button. Next change vehicle, then do the same with a new vehicle info. I think up to 3 vehicles can be compared. Once all added, click on 'comparison list at the top, where it will open a new page with the data.

Incidentally, it seems to be petrol BMW models rather than their equiv. diesels that use the same MAFs. (the M5 being one)

Whilst trying to find it, I found a few other interesting snippets. (probably already known) Some Rover 400 MAFs are also used in a Ferrari 360 :eek: (I know they are just sensors for collecting data, but apparently the price is $750 for the Ferrari branded one (http://www.ferrarichat.com/forum/143515872-post5.html), with the Rover/Honda one being $210!

Another site I came across that may be of interest for you Harry was THIS (http://www.maf2maf.com/) one, although with your previous experiments, I suspect you may have come across it yourself.


For people worried about fakes Bosch has a verification site HERE (http://www.protect.bosch.com/).

[HarryM1BYT]

For people worried about fakes Bosch has a verification site HERE (http://www.protect.bosch.com/).

That method, using a more reliable MAF, then using table in maybe a pic, was one of my suggested methods to bypass paying through the nose for the correct, genuine Bosch MAF. I was also suggesting a similar method for testing a fan or blower, his adaptor though, seems to be much more complex a system than I was suggesting.

The correct one is not that long lived, for what they cost, so I was looking for a work around - a longer lasting and cheaper fix, than our being over a barrel to Bosch.

As we all keep saying on here - there are lots of fake Bosch MAF's available and lots of genuine Bosch MAF's being sold as being suitable for the 75 diesel. The fakes are a complete waste of money, the ones described as 'suitable' a very poor compromise indeed.

We have Bosch to thank for the mess, overcharging us all for a 75's MAF for which they charge BMW owners a more reasonable sum for an identical MAF.