Freelander 1 TD4 BLACK SMOKE WITH NO LOSS OF POWER

I have a TD4 2005 Auto which black smokes excessively on acceleration.
There is no loss of power as it goes like a stabbed rat.
All filters inc crankcase filter have been replaced. Intercooler hoses all good.

Any thoughts/suggestions that are relevant (!) will be welcome

Steve

faulty air-intake-temp.-sensor .. maybe ?
https://www.landyzone.co.uk/land-rover/and-the-black-smoke.224520/
or ..
over fuelling maf-sensor possibly ?
http://tuning-diesels.com/75Zt/R75maf.htm

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other links :

td4 engine faults :
http://tuning-diesels.com/75Zt/R75faults.htm
.pdf download at this thread ,,
https://www.landyzone.co.uk/land-rover/75-zt-td4-fault-diagnosis.203935/

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Thanks. Really interesting. Almost an identical fault to mine.

MAF sensor overfuelling?

EGR stuck maybe ? remove check and clean if you have to also remove and clean the MAP sensor, with regards to the MAF unplug and see if it is any worse if not could point to MAF, but check the easy things first.

So. Have bitten the bullet and replaced the MAF and air intake sensor, unfortunately without any real change.
Cant help but think its been remapped due to the performance.
Does anyone know if a dealer can return to stock ?

MAF on a diesel has nothing to do with fuelling. It is there to tell the ECU how much exhaust gas is being ingested when EGR is being applied. However a faulty MAF can lead the ECU to be confused and misinterpreting air conditions.

It's is possible for a Bosch MAF to over read air flow as well as under read it. If it's over reading then the ECU will over fuel, giving plenty of power but lots of smoke, particularly at below 2500 Rpm.
Contrary to what, misinformed people say. The ECU on the M47 uses the MAF signal to fine tune the engine's fueling requirements, in addition to emission control via the EGR. If the MAF signal is low, power will be lacking below 2500 Rpm. If the MAF signal is high, the engine will have lots of power below 2500, but possibly lots of smoke too.
Unplugging the MAF is a good test. If power is lost, the MAF is likely over reading. If power increases, the MAF isn't retuning a strong enough signal.
A stuck EGR valve can cause black smoking but this normally gives a power reduction, particularly at low Rpm.

Thanks for the replies.
New Bosch Maf fitted. It transpires the car was mapped previously but the guy I bought it from asked for it to be returned to stock due to poor mpg. Its still poor mpg but goes like the clappers, so I'm wondering if its actually still mapped. He's trying to find out the remapping company for me.

You can map a diesel engine too much. There's only so much air the standard turbo can supply. A diesel makes more power by adding more fuel. However extra fuel is only any good if there's sufficient air to burn it. Black smoke suggests that the maximum useful fuel increase has been exceeded. This will give rise to poor Mpg and possibly accelerated bore/ring wear.
Just a thought.
Has the EGR valve been blanked? If not, the valve could be lifting off its seat under boost, diluting the incoming air charge. This gives the same effect as over fueling.

Nodge68 said:

You can map a diesel engine to much. There's only so much air the standard turbo can supply. A diesel makes more power by adding more fuel. However extra fuel is only any good if there's sufficient air to burn it. Black smoke suggests that the maximum useful fuel increase has been exceeded. This will give rise to poor Mpg and possibly accelerated bore/ring wear.
Just a thought.
Has the EGR valve been blanked? If not, the valve could be lifting off its seat under boost, diluting the incoming air.

Click to expand...

I have a blank coming this week funnily enough

Nodge68 said:

It's is possible for a Bosch MAF to over read air flow as well as under read it. If it's over reading then the ECU will over fuel, giving plenty of power but lots of smoke, particularly at below 2500 Rpm.
Contrary to what, misinformed people say. The ECU on the M47 uses the MAF signal to fine tune the engine's fueling requirements, in addition to emission control via the EGR. If the MAF signal is low, power will be lacking below 2500 Rpm. If the MAF signal is high, the engine will have lots of power below 2500, but possibly lots of smoke too.
Unplugging the MAF is a good test. If power is lost, the MAF is likely over reading. If power increases, the MAF isn't retuning a strong enough signal.
A stuck EGR valve can cause black smoking but this normally gives a power reduction, particularly at low Rpm.

Click to expand...

Fuelling is controlled subject to power/throttle demand and has nothing to do with the MAF sensor. Diesels are throttled by fuel not by air.

wammers said:

Fuelling is controlled subject to power/throttle demand and has nothing to do with the MAF sensor. Diesels are throttled by fuel not by air.

Click to expand...

Old mechanical diesels fueled based throttle position. Those days are long gone. Modern diesel control calculates fuel requirements based on many factors, including how much air is entering the engine. It measures this air with the MAF. If the MAF signal is incorrect, the fueling will also be incorrect. If the MAF is open circuit or short circuit, the EDC will ignore it, fueling on throttle position alone.
Giving incorrect information isn't helping the op.

Nodge68 said:

Old mechanical diesels fueled based throttle position. Those days are long gone. Modern diesel control calculates fuel requirements based on many factors, including how much air is entering the engine. It measures this air with the MAF. If the MAF signal is incorrect, the fueling will also be incorrect. If the MAF is open circuit or short circuit, the EDC will ignore it, fueling on throttle position alone.
Giving incorrect information isn't helping the op.

Click to expand...

So stop doing it then. MAF is for EGR control not for fuelling.

wammers said:

So stop doing it then. MAF is for EGR control not for fuelling.

Click to expand...

Once again, you prove you have a complete lack of understanding on anything Freelander, or modern for that matter.
Stop posting crap, it isn't helpful.

Nodge68 said:

Once again, you prove you have a complete lack of understanding on anything Freelander, or modern for that matter.
Stop posting crap, it isn't helpful.

Click to expand...

Diesel engines are throttled by fuel NOT by air. Reducing the amount of combustible air by use of EGR and variable vane turbos to reduce boost when not required are ways of reducing NOX production. But the MAF does not control fuelling. It measures the amount of exhaust gas being ingested by the engine The reduced airflow when EGR is active = the exhaust gas being ingested. The ECU then controls EGR modulation subject to readings from the MAF to maintain the correct balance of air/exhaust gas to cool the combustion and reduce NOX. Fuel remains the same. It is not i that has the complete lack of understanding. I suggest you find out how diesel engines work. If you want a diesel to run at 1000 rpm fuel is injected to achieve that rpm. If you want it to run at 2000 rpm fuel is increased to attain that speed, the air remains the same. At idle the air/fuel mixture ratio can be well in excess of 100 to 1. There is ALWAYS more air in the cylinder than is required. This produces NOX, reducing the amount of air to just above that which is required to service the power/rpm need as set by the throttle requested power demand request and reduces emissions. DO YOU understand that?

Have to agree with

have to say the above description is how diesels work wammers has described it perfectly, not trying to butt in, maf signal does have a bearing on fuel input,but its really there to measure the amount of air going in

wammers said:

Fuelling is controlled subject to power/throttle demand and has nothing to do with the MAF sensor. Diesels are throttled by fuel not by air.

Click to expand...

First there was this ^^^^.
This is inaccurate information. This is what I was referring to.

rangerovertoy said:

have to say the above description is how diesels work wammers has described it perfectly, not trying to butt in, maf signal does have a bearing on fuel input,but its really there to measure the amount of air going in

Click to expand...

You have just said exactly what I was saying. The ECU references the MAF signal for fueling.
There's no need for Wammers to give the remedial explication on how a diesel, in general works.
What I'm saying correct. The BMW MR47 ECU uses the MAF signal to calculate correct fueling.
If the MAF signal is incorrect, the fueling will also be incorrect.

rangerovertoy said:

have to say the above description is how diesels work wammers has described it perfectly, not trying to butt in, maf signal does have a bearing on fuel input,but its really there to measure the amount of air going in

Click to expand...

It is there to measure the amount of exhaust gas going in when EGR is active. Serves no other purpose. on this vehicle. This car will be EU 3 that is why it has a variable turbo plus EGR with feedback. EU 2 was EGR with feedback (MAF sensor). EU 1 EGR with no feedback. NO MAF. EU 4-5 and 6 are significantly more complicated the later ones with diesel Lambda probes and DPFs.