Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Diamond Black Geezer on 24 January 2011, 14:26:28

Title: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 24 January 2011, 14:26:28
Where is the MAF sensor, on a 2.5TD?? I really hate asking such a simple question, but ive been all over the forum / under the bonnet, cant find anything that looks promising.

This is a development to a previous thread ( http://www.omegaowners.com/forum/YaBB.pl?num=1294909143 )  regarding a possible stuffed Autobox, I've been investigating other peoples threads with similar issues and it's possible a faulty MAF sensor could be causing the problems.



Incidentally the replaced/cleaned out selector switch underneath the car seemed to work like a dream, but now gearchange is as limpmode as ever!

Thanks as ever oofmen and oofwomen  :y :y
Title: Re: MAF Sensor on a TD??
Post by: aaronjb on 24 January 2011, 14:32:29
What year is your TD?

Early 2.5TD don't have a MAF, only a MAP sensor which is near the passenger suspension turret and is a small black cube about 1" on each side with one electrical connection and one vacuum connection - see here for a picture (http://www.omegaowners.com/forum/YaBB.pl?num=1279907070/2#2).

Later 2.5TDs had a MAF and a MAP - the MAF is located in the air pipe on the outlet side of the air filter box. You can't miss it, it's a big square thing in the ribbed pipe with an electrical connection. I think the MAF came in around '97/8?
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 24 January 2011, 14:42:17
Many thanks!

It's a '98 R Reg. Im not 100% sure how the MAF could be causing a gearbox issue, but wont rubbish the idea, I have learned to keep an open mind with Omegas!!
Title: Re: MAF Sensor on a TD??
Post by: aaronjb on 24 January 2011, 14:57:14
MAF and MAP are used to calculate 'engine load' which is one of the components the gearbox will most likely use to calculate 'desired gear' along with road speed and engine RPM.
Title: Re: MAF Sensor on a TD??
Post by: Welung666 on 24 January 2011, 15:03:40
It should have a MAF, try unplugging it and see if it improves any of your symptoms. Unplugging it drops it back to basic mode so it'll be a little flat up to about 2,500rpm but should pick up after that :y
Title: Re: MAF Sensor on a TD??
Post by: zirk on 24 January 2011, 15:18:05
My very first 2.5td had what I thought was a slipping / loss of power auto, wouldn't even climb a kerb head on from stand still, turned out to be the Maf.
Title: Re: MAF Sensor on a TD??
Post by: hoofing it on 24 January 2011, 16:58:42
Quote
What year is your TD?

Early 2.5TD don't have a MAF, only a MAP sensor which is near the passenger suspension turret and is a small black cube about 1" on each side with one electrical connection and one vacuum connection - see here for a picture (http://www.omegaowners.com/forum/YaBB.pl?num=1279907070/2#2).

Later 2.5TDs had a MAF and a MAP - the MAF is located in the air pipe on the outlet side of the air filter box. You can't miss it, it's a big square thing in the ribbed pipe with an electrical connection. I think the MAF came in around '97/8?
Is the map sensor on early td's not under the manifold behind the egr valve in the later one's the hole was blocked with a bolt :-/
Title: Re: MAF Sensor on a TD??
Post by: charlie on 24 January 2011, 17:55:49
I think the map is in the same place on all td's. The later ones with the bolt in replaces air intake temp sensor
Title: Re: MAF Sensor on a TD??
Post by: Pitchfork on 24 January 2011, 18:35:08
Quote
What year is your TD?

Early 2.5TD don't have a MAF, only a MAP sensor which is near the passenger suspension turret and is a small black cube about 1" on each side with one electrical connection and one vacuum connection - see here for a picture (http://www.omegaowners.com/forum/YaBB.pl?num=1279907070/2#2).

Later 2.5TDs had a MAF and a MAP - the MAF is located in the air pipe on the outlet side of the air filter box. You can't miss it, it's a big square thing in the ribbed pipe with an electrical connection. I think the MAF came in around [media]'97/8?[/[/media]quote]
My old October 1996 Traktor had a MAF on the airbox
Title: Re: MAF Sensor on a TD??
Post by: aaronjb on 24 January 2011, 19:02:51
Quote
My old October 1996 Traktor had a MAF on the airbox

Aha .. I was trying desperately to remember what year yours was when writing that post - I was convinced it was a '97, but apparently .. t'was not :)

Oh and Charlie is right - MAP sensor in the same place on all TDs, air temp sensor got deleted when the MAF came in (it does a similar job). The vac nipple for the MAP sensor is under the plenum a little ways behind the EGR valve, though.
Title: Re: MAF Sensor on a TD??
Post by: robg1984 on 25 January 2011, 17:17:34
thanks for all the advice ive unplugged the maf tonight after i got home (travelling at about 45 down the motorway as gearbox warning was on and it didnt want to go nowhere in any gear!). Started her up and gearbox warning light had gone off took her for a spin and shes pulling fantastic!!!
Fingers crossed this is it sorted ;D
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 26 January 2011, 00:21:42
Looks like were on the lookout for more free car parts!!

This cars loads of hassle, but look on the bright side, it never actually cost you any money!!!  :D :D ;D ;D :D :D ;D :y :y :D ;D
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 26 January 2011, 20:55:18
OK Update to this.

-A decent 2nd hand Gear selector switch has been fitted, which was cleaned out before fitting.
-The car ran beautiful for 24hrs, then rubbish again. On inspection It appeared the nylon bush was slightly out, so using a tiny allen key this was aligned, but to no avail. It was only out by a fraction anyway.
-Also the selector lever was tweaked in length, just to make sure all was 'as far back as it will go' when in P.

-The MAF has been unplugged, as has the MAP sensor. Again, this seemed to work, but later in the afternoon the car started running like an asthmatic sloth again.

All my instincts are telling me its still MAF/MAP/Selector switch related, but all the evidence seems to be saying 'replace the gearbox'. I'm really not keen on doing this until all avenues have been fully explored.

Could we have missed anything / done something wrong!!?

This is getting ridiculous now, me and my mate are still defrosting after a whole afternoon wasted. I just get the impression its something ridiculously simple, or that we've done wrong.

Thanks in advance!  :'( :'(
Title: Re: MAF Sensor on a TD??
Post by: Welung666 on 26 January 2011, 21:16:23
Any codes stored?
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 26 January 2011, 21:25:33
Tried the old paperclip test almost immediately after buying the car, and its one of them TDs you cant paperclip. Grrr!

That said will be able to give you a full list, as my mate has a code reader in the post, so he'll be posting these tomorrow.

Ta.
Title: Re: MAF Sensor on a TD??
Post by: Welung666 on 26 January 2011, 21:30:34
If it does turn out to be the MAF have a look for some of these part numbers...

PIERBURG : 7.22184.50.0

BMW : 13 62 2 246 084, 2 246 084

OPEL : 836625,   90528813

I ended up paying £25 for one off eGay ;)
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 26 January 2011, 21:50:58
Oh, cheers Welung.

I only found out today that all MAFs arent born equal ( ;) ) so they're useful.


Dare I mention that a friend of mine may have jabbed a screwdriver inside the MAF, which may have 'disconnected' some of the internal components, and 'placing' them in the gutter...? I literally do not mind, as it is his car, after all  8-)
Title: Re: MAF Sensor on a TD??
Post by: Welung666 on 26 January 2011, 22:00:12
Quote
Oh, cheers Welung.

I only found out today that all MAFs arent born equal ( ;) ) so they're useful.


Dare I mention that a friend of mine may have jabbed a screwdriver inside the MAF, which may have 'disconnected' some of the internal components, and 'placing' them in the gutter...? I literally do not mind, as it is his car, after all  8-)

I have a feeling you may have discovered part of the problem! Have the tool leave the tools alone ;D ;D
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 26 January 2011, 22:02:40
Haha! He's on the forum, careful what you say hehe.

Though if Im correct the car should run 'fine' (although not perfect, obviously, that's why they put one in) without a MAF fitted, yes? Or will the gearbox issue still be there unless a working MAF is plugged in?
Title: Re: MAF Sensor on a TD??
Post by: Welung666 on 26 January 2011, 22:05:29
Unplugging the MAF drops it back to basic mode. It'll run fine if a little thristy and flat as a witches tit until the turbo fires up around 2500rpm. Best to wait for the code reader and find out what is showing up really :y

P.S. The tool knows I'm only jesting ;) ;D
Title: Re: MAF Sensor on a TD??
Post by: Marks DTM Calib on 26 January 2011, 22:08:02
MAP sensor is ESSENTIAL on the diesels and is not likely to cause an issue (just check the feed pipe is clear).

I have long suspected that the MAF on these does nothing more than limit the fueling at max load so as to limit smoke production so yes, I can see that backing the fuel off.

Ow yes, MAF sensors are quite fragile so go gentle with them  ;D
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 26 January 2011, 22:16:13
Ah, thanks to Mr DTM and Mr Welung, have read elsewhere that the MAF provides some data the gearbox uses. Unplugging should temporarily 'cure' the 'box issue, thus proving a new sensor is required.

Will look forward to finding out what codes are stored etc.


Personally have experience with AR25 Omegas for over 5 years, without a single spot of trouble. Looks like my mates fallen out of the badluck tree and hit every gearbox branch on the way down.
Title: Re: MAF Sensor on a TD??
Post by: Marks DTM Calib on 26 January 2011, 22:17:38
Quote
Ah, thanks to Mr DTM and Mr Welung, have read elsewhere that the MAF provides some data the gearbox uses. Unplugging should temporarily 'cure' the 'box issue, thus proving a new sensor is required.

Will look forward to finding out what codes are stored etc.


Personally have experience with AR25 Omegas for over 5 years, without a single spot of trouble. Looks like my mates fallen out of the badluck tree and hit every gearbox branch on the way down.

I cant see the gearbox getting anything useful from a MAF signal wise so would suggest thats a 'herrang rouge'
Title: Re: MAF Sensor on a TD??
Post by: Diamond Black Geezer on 26 January 2011, 22:42:28
Thanks for that.

Will probably be using my dad's TD as a donor for MAF and Selector switch (but only for one run around the block Im told. For some incredible reason, he doesnt want his daily driver stripping of its ability to change gear!!)

Just to confirm that it ISNT the selector switch thats at fault/we've done something wrong while cleaning and refurbing

Look forward to the pl"My Naff Code Reader" test results tomorrow.
Title: Re: MAF Sensor on a TD??
Post by: mrgreen on 26 January 2011, 23:26:27
well if it runs o.k for 24hrs then you have to rule out the box, it's gotta be those pesky computers! i always suspected the maf sensor on my volvo for the same symptoms and if i still had it i would be changing it straight away, oh well money lost  :-[