Thread: TD5 Mafs etc....

Originally Posted by 5teve

HI Guys

we have 2 TD5's 1 disco II auto and 1 defender 110 both of 2002 vintage.. and both with tombies mild chip (which have been great)

The disco has been running poorly for a while supping great quantities of fuel (550k per tank down from over 800) however try as hard as i can i cant get it to smoke which i would assume using excess fuel it would do.. its also not running overly quick... with performance probably being down on what it was. i have tested cleaned and tested the MAF with it looking ok, however having now disconnected it it looks (at less than halfway through a tank) like the k's are back up there and it feels more responsive.

1st question .... How is the MAF sensor causing this? what influence does it have over what fuel is being chucked in there... or could it be the fact the egr system isnt playing nicely.. (yes i know i need to get rid!)

ok to the defender now.. this goes well albeit a bit 'peaky' when the boost comes on if you give it too much loud pedal. however on take off it always seems a bit weak with the revs dipping and then picking up nicely. the problem i have is that in the first couple of hundred revs it chuffs a lot of smoke like its over fueling. I dont remember it doing this when it was first chipped. Change gear and the same happens again and it does this right through the gearbox. Tow the boat and its the same ... maybe worse. Thing is that fuel economy is good. I get about 1000k's to about 105L so cant complain for urban travelling with lots of stop start..

This morning i disconnected the MAF after seeing some people say after search on here that the MAF could make things smoke if its not right. The result, from what i can see, very little smoke if any from it when it takes off.. and hard to make smoke by pushing hard.. the only reall difference is it is less peaky and the accelerator seems a bit dead to start with.. still seems to pull quite well tho... maybe fractionally not as hard as with the MAF connected.

2nd Question... could this really be the MAF too... and why is it causing these symptoms as i have read the MAF doesnt really do a great deal regards fuelling etc...

3rd Question... if i need 2 MAFS where am i best to get them from?

Thanks

Steve

There's a couple of things it could be, the MAF, which will need to have some flow readings to see (someone with a Nanocom) give it a clean with MAF cleaner as well, reading under load are 500+, 60 to 80 at idle.

AAP sensor, just clean it with MAF cleaner (don't touch the sensor probe)

Wastegate modulater, $50 from any LR parts supplier, this will cause low power and higher fuel economy (Disco only)

Before you go out and buy MAFs, try cleaning them first, if you haven't got any MAF cleaner, try carby cleaner or contact cleaner, let them dry naturally and don't touch the elements with anything other than the cleaner.

Baz.

Originally Posted by Redback

There's a couple of things it could be, the MAF, which will need to have some flow readings to see (someone with a Nanocom) give it a clean with MAF cleaner as well, reading under load are 500+, 60 to 80 at idle.

AAP sensor, just clean it with MAF cleaner (don't touch the sensor probe)

Wastegate modulater, $50 from any LR parts supplier, this will cause low power and higher fuel economy (Disco only)

Before you go out and buy MAFs, try cleaning them first, if you haven't got any MAF cleaner, try carby cleaner or contact cleaner, let them dry naturally and don't touch the elements with anything other than the cleaner.

Baz.

Thanks Baz

I should of mentioned that i have cleaned most of the sensors on both vehicles... with MAF cleaner...

The aap sensor? is that the one on the airbox? or the inlet manifold.. i'm assuming ambient air pressure so the box..

Regarding the disco, it has a new modulator (well a year or so old) judging by the boost curve (i have a nanocom) its working and doing its thing, and the air flow readings were seemingly normal.. at idle and through the rev range (accoring to the maf test posts) however economy was very poor and power didnt seem right.. with the MAF disconnected there is a difference for the positive. Its quicker and seems more economical.. i havent checked the EGR but i will be looking at removing that shortly also. its not a huge cost item so will probably replace it on the disco...

The defender, drove worse with the MAF disconnected lower power low down but very little in the way of smoke on take off.. i dialled a bit more boost on the defender yesterday and am monitoring the smoke on take off.. i didnt notice much this morning. i'm assuming the maf is working ok, i am wondering if the clutch switch is working tho.. so need to check it on the nanocom.. as i think that alters the map a little.. so could explain it.. one other thing i noticed is that the Oring on the airbox to MAF is missing (cant find the part no anyone know it?) so improvised with a neoprene gasket as the maf had dust in it (as did the air box) should dust be getting past the filter? a bit worrying! i may have to wash it all out as its filthy on the intake side...

Thanks

Steve

Originally Posted by 5teve

Thanks Baz

I should of mentioned that i have cleaned most of the sensors on both vehicles... with MAF cleaner...

The aap sensor? is that the one on the airbox? or the inlet manifold.. i'm assuming ambient air pressure so the box..

Regarding the disco, it has a new modulator (well a year or so old) judging by the boost curve (i have a nanocom) its working and doing its thing, and the air flow readings were seemingly normal.. at idle and through the rev range (accoring to the maf test posts) however economy was very poor and power didnt seem right.. with the MAF disconnected there is a difference for the positive. Its quicker and seems more economical.. i havent checked the EGR but i will be looking at removing that shortly also. its not a huge cost item so will probably replace it on the disco...

The defender, drove worse with the MAF disconnected lower power low down but very little in the way of smoke on take off.. i dialled a bit more boost on the defender yesterday and am monitoring the smoke on take off.. i didnt notice much this morning. i'm assuming the maf is working ok, i am wondering if the clutch switch is working tho.. so need to check it on the nanocom.. as i think that alters the map a little.. so could explain it.. one other thing i noticed is that the Oring on the airbox to MAF is missing (cant find the part no anyone know it?) so improvised with a neoprene gasket as the maf had dust in it (as did the air box) should dust be getting past the filter? a bit worrying! i may have to wash it all out as its filthy on the intake side...

Thanks

Steve

Yes that's the one, dust getting past the air filter is a common thing for the TD5, I've tried a few things trying to stop this, so far the only one that has worked is getting a foam Filter (Uni- Filter) it seems to seal better.

Maybe run an injector cleaner through a couple of tanks and clean or remove the EGR, if you do this get some silicon hoses, your standard hoses may be delaminating or getting too soft, this can cause low power as well.

Baz.