Maf & Loss Of Power

[yorkmann]

Hi, I have a 1.9tdi Galaxy and have been having a problem for a while with it having a lack of power between 2-3000 rpm in 4-5 gear which is a bit of a problem on the motorway when trying to overtake with it being gutless.

 

My question is, I know alot of people on here have posted about replacing the maf and it cures this what i would like to know is if i put it on wds diagnostic tool and it does'nt show that i have a problem what could be causing it or is it right that i have heard that this fault may very well not be picked up by the computer.

 

A friend of mine who did the test for me has said that if it was the maf the computer would have picked it up, so who is right??

[seatkid]

The MAF calibration is up the spout but the MAF "thinks" its alright and the computer "thinks" its alright......just that the air is a bit thin today......or your filters clogged up.....it takes a trained technician to interpret the indicated flow rates and as we proved time and time again, these people don't exist.

 

 

Classic symptoms, 90% probability Maf is knacked

[Dave-G]

:) But the scientific way to accurately test that device is... B)

 

:) unplug it and test drive. :)

 

:P if it runs with zest tha maf is knacked :lol:

EDIT to host this pic

[gregers]

as i dont have a deisel(yet)why does it run better with the maf disconected?and if it runs better whys it there in the 1st place?

 

regards gregers

[Masked Marauder]

If it runs badly with it connected it is because the computer running the engine (the ECU) does not know it is faulty.

 

When you unplug the MAF the ECU knows it is not working. The ECU then switches to a fixed fuel mapping which is basically the same fueling and timing as a traditional diesel would be running. This then gives better performance than running with a faulty MAF.

 

Clearly dynamic mapping is superior to this "fall back" mapping, which is why the MAF is there in the first place.

[yorkmann]

Cheers for the help guys tried running it with the maf disconnected and seemed to make no differance but was no worse any ideas, but think i will replace it anyway as the full part is only

[seatkid]

In my case when I unplugged my faulty MAF it made no difference....the ECU presumably had given up on it.

[Danny Boy]

Yorkman

 

Where did you get the price for the MAf from, I think i need a new one??

[paulmpaciorek]

Danny Boy

 

Ive just bought one from Ebay

[yorkmann]

Danny boy got the new maf from swedish & german for

[Guest vr6galaxy]

Or just click on.... gsfcarparts

[italiastar]

Sorry to sound dim, but how can I identify the MAF and where to unplug it?

[seatkid]

looky here

[italiastar]

Thanks - your a star!!!!

 

I assume to test it, you run the car with the MAF "unscrewed" - it's not just a case of disconnecting the multiplug?

[seatkid]

No! Just unplug the electrical connector - no change or an improvement in performance points to a faulty MAF (if no change check those vacuum pipes just in case!)

[Guest stormchaser]

I've just done the same on my 2.8 V6. It just didn't seem to be running right, lack of power being the biggest sympton. Unplugged the MAF, no difference or possibly a slight improvement. Replaced the MAF (Ebay

[Bobboash]

Hi

 

This may help. About a year ago my engine warning lamp started flashing and I suffered loss of power etc. I found the cause of the lamp flashing to be a faulty brake switch on the pedal so I sprayed with WD40 and brake lights worked again and the flashing light went out but I still suffered the loss of power.

I then changed the switch all together (costs about

[Danny Boy]

Just changed by MAF, got from GS&F for

[Guest seatalhambra]

Seeing the number of maf problems i wonder if my power loss and dodgey auto gear changes are relate to it. yesterday the 3-4 gearchange over revs whengoing up. it usually seems to change at the wrong revs compared toif your were driving a manual.. to early....

i tried locking the tiptronic in manual and it seemed to be responding similar to a manual box..

any thoughts

[Guest Tim Here]

3 months ago I had to replace my MAF and I was advised by Swedish and German to replace it with a Bosch which works out about

[tim-spam]

I think my Alhambra TDI (115) may be suffering from MAF problems. The symptoms are as follows:

When accelerating from around 1500 rpm, the turbo cuts in and the car accelerates pretty well until around 2000 rpm when it feels as if I have lifted the accelerator. In the lower gears, this is not so noticeable as the car accelerates through this fairly easily, but in 4th, 5th and 6th it is much more noticeable. If I release the accelerator pedal and then slowly re-apply it, the car accelerates fairly well so long as the pedal is moving, but when it reaches the floor acceleration tails right off again.

This behaviour is worse in warm weather - for example, this morning, it wasn't too bad - although it seems to be getting steadily worse from being just noticeable on a hot day a few weeks ago to now being noticeable all the time and pretty poor on a hot day.

I tried unplugging the MAF and the performance was much worse, so it obviously hasn't failed completely, and there is no evidence of any resetting when the ignition is switch off.

What do others think?

Many thanks for a great forum.

Tim

[Guest edthedead]

The problem I was having seems to have been cured by changing the boost sensor...

[GSMGuy]

Ed, was the boost pressure sensor (T-MAP) in the manifold pipe near the battery changed, or the boost pressure control valve/solenoid (behind the engive on the bulkhead)

 

I am pretty certain that the former is causing my problems too... How much did you pay (if that's what you changed)

 

Mike

[GSMGuy]

Right an Update - A known faulty MAF arrived in the post for me today - many thanks Seatalhambra!!!

 

Anyway, swapped it and the car is now gutless, and still has the boost cutting out at 300 rpm in top.. So I thinks the MAF is ruled out as ok..

 

All things really seem to be pointing to the T-MAP sensor.....

 

Also I am gonna post this in the 3 similar threads that are going at the moment, as it's getting hard to keep up!! Can a mod possibly combine the threads??

 

http://www.fordgalaxy.org.uk/ford/index.ph...=15&?do=findComment&comment=40532

 

http://www.fordgalaxy.org.uk/ford/index.ph...&hl=boost&st=15

 

http://www.fordgalaxy.org.uk/ford/index.ph...topic=5735&st=0

 

All the above threads seem to be about the same problem..

 

Mike

[Guest D.McB]

I am pulling my hair out ( what's left of it) with a power/acceleration problem with my ghiax auto tdi.

The car suddenly loses acceration having very low power, so bad that caravans overtake me, very noticable going uphill. If I stop turn ignition off then problem dissappears until the next time....

I have had the car into the Seat dealer who service it, they cannot find a fault code ( mass air flow sensor suggested) advised try ford dealer who charged