2003 Freelander TD4 2K misfire

Hi all, I have a 2003 Freelander TD4 which has an intermittent misfire that is progressively getting worse. It seems worst at around 2000rpm, particularly under a light throttle. I have had 4 new injectors fitted, but the problem came back within a few days. Took the car back to the garage, who told me they then calibrated the new injectors to match the car. Misfire went away for a couple of weeks and is now back with vengeance.
Doing some internet research, it looks like this 2K misfire is quite common on TD4 Freelanders. Perhaps something to do with the Turbo boost controls? No smoke from the exhaust and otherwise everything seems fine.
Can anyone offer any insight into this problem and the solution.

Have you got egr bypass fitted? It appears that 2k misfire is worse if yes!! No one seems to be able to get to bottom of it. Wonder what garage did as I don't know of any calibration of injectors that is possible on the TD4 !!

Hi Andy, thank you for getting back to me.
I have had the misfire problem for about a year, steadily getting worse as I mentioned. I had the EGR valve fitted until 2 weeks ago, when I fitted the EGR blank to see if that would help the misfire. I would say it has made no difference at all having it fitted, as the misfire was as bad as ever.
I've just had the Freelander over my inspection pit this evening, and have disconnected the pneumatic tube from the turbo control valve to the actuator on the turbo itself, by way of a test, to stop the boost varying. Took it for a test drive and I would say the misfire did improve after 15 minutes driving. Obviously no turbo boost, but no misfire at present either. The misfire does tend to come and go, so I need to see how things go after I have driven some more this week.
Reading up on this, it looks to me like the ECU has some way of "tuning" the injectors by varying their timing, depending on factors like engine condition and various other things. I'm wondering if the 2K misfire issue is caused by a turbo problem, giving false information (via the inlet pressure sensors) to the ECU, which then varies the timing pf the injectors and causes the misfire. I may be 100% wrong, it is just a theory. See if the misfire gets better this week.

Nodge will be along shortly, he has a good knowledge of the M47 (and others) engine and has given this subject no mean amount of brain power !!!

Thanks Andy. Be good if we can sort this, as it is a good up-together car that I really like, and having just shelled out nearly £1k for 4 new injectors, I would like to have a few more years use out of it.

Anthony Raybould said:

Can anyone offer any insight into this problem and the solution

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No sure solution that I know of. Mine also does it, and has done since I've owned the car. I gave up looking for a nonexistent fault, so I now ignore it. It's not there all the time, just light throttle, normally if it's a slight downhill section of road. If I hold mine at 2K Rpm off load, then it starts to puff blue smoke as well as misfire.

I just ignore it.

I'm sure it's something to do with oil contamination of the intake air charge, possibly through the breather circuit. However I've never actually got round to working out if this oil contamination can be eliminated. That's my thoughts on it anyway, it's not injectors or the EGR system, that I do know.

Thanks Nodge68. I did notice some oil in the intake hoses a few weeks ago and I wondered if that was normal. Maybe it is getting in through the turbo via a leaking seal, or the crankcase breather perhaps. Something to look into. My misfire is too bad to ignore unfortunately. Will post more if I have any breakthroughs.

Anthony Raybould said:

Thanks Nodge68. I did notice some oil in the intake hoses a few weeks ago and I wondered if that was normal. Maybe it is getting in through the turbo via a leaking seal, or the crankcase breather perhaps. Something to look into. My misfire is too bad to ignore unfortunately. Will post more if I have any breakthroughs.

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my last FL1 started the 2K misfire after some 6 months of ownership,only did it when the air temperature was above 12 degrees always OK in winter . I reasoned that it had something to do with fueling , the M47 is a lean burn engine and it seemed that it was running even leaner in warm weather causing the misfire. the AIT sensor is easily accessable in the MAF so I increased the value of the resistive sensor by 1.8 K ohms to increase the fuel to air ratio and that cured the misfire exept on very hot days when the misfire would return slightly, there was no effect on fuel consumption strangely so the extra fueling must have been minimal. I ran the car like this for some 40000 miles with no problems. In trying to find a cure I changed the injectors with no result and did all the normal checks eg vacuum pipes inlet manifold clean etc.I exchanged the car recently for an HSE with much lower milage as we do some 15000 miles a year and the other car had done 190000 miles ,so far my FL1 ownership has been very positive it is great to drive and economical, does about 10mpg better than the 110and much more comfy

110tim said:

my last FL1 started the 2K misfire after some 6 months of ownership,only did it when the air temperature was above 12 degrees always OK in winter . I reasoned that it had something to do with fueling , the M47 is a lean burn engine and it seemed that it was running even leaner in warm weather causing the misfire. the AIT sensor is easily accessable in the MAF so I increased the value of the resistive sensor by 1.8 K ohms to increase the fuel to air ratio and that cured the misfire exept on very hot days when the misfire would return slightly, there was no effect on fuel consumption strangely so the extra fueling must have been minimal. I ran the car like this for some 40000 miles with no problems. In trying to find a cure I changed the injectors with no result and did all the normal checks eg vacuum pipes inlet manifold clean etc.I exchanged the car recently for an HSE with much lower milage as we do some 15000 miles a year and the other car had done 190000 miles ,so far my FL1 ownership has been very positive it is great to drive and economical, does about 10mpg better than the 110and much more comfy

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Thank you 110 Tim. I have just ordered a pack of 1.8 KOhm resistors so I will pop one in and see if that does the trick.

mine misfires at 2000rpm .. if ..
the revs are raised when in neutral gear
( no misfire when driving .. even at part go-pedal
( well .. none that i can detect ..
and .. if a bosch maf is used ..
( no puffs of smoke either

with the pierburg maf / ron box ..
no misfire at all ..

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Anthony Raybould said:

Thank you 110 Tim. I have just ordered a pack of 1.8 KOhm resistors so I will pop one in and see if that does the trick.

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just to confirm that you have to put a 1.8k resistor in series with the existing AIT sensor resistor so it will involve cutting the AIT resistor lead and soldering the new 1.8k resistor in series with it,the theory is that if the engine ECU is receiving info from the AIT telling it that the air temperature is low),and the 1.8k resistor will make it artificially low), then it will put in extra fuel as the air charge is more dense.Hope it works out for you it certainly sorted mine out but it took a little time to come to a solution. This obviously is covering up the real problem which no one seems to have discovered as yet not even on the BMW forums

110tim said:

only did it when the air temperature was above 12 degrees always OK in winter

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Mine is more random than that, but I've noticed it missing more often when it's cold.

Might be worth putting a variable resistor in and playing for optimum fuel efficiency vs misfire? Mine has the hiccough at 2100 ish rpm. It really is nothing though. Interstingly my TD4 always flashes the glow light even on sunny hot days. Weird but there we are. Maybe it thinks it is colder than it is. Are these fired from water or air temp.???

andyfreelandy said:

Might be worth putting a variable resistor in and playing for optimum fuel efficiency vs misfire? Mine has the hiccough at 2100 ish rpm. It really is nothing though. Interstingly my TD4 always flashes the glow light even on sunny hot days. Weird but there we are. Maybe it thinks it is colder than it is. Are these fired from water or air temp.???

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I started with 1.5K and ended up at 1.8K which seemed to do the trick unless it was very hot then the dreaded misfire would come back erratically. When it started after about a year of ownership I was really worried that something horrible was about to happen until I found this amazing forum and found that other people had been having the problem as well. Many thanks to the folks who put some very interesting posts on here with their problems and those knowledgable folks who provide the answers, it makes owning a Freelander with its problems so much easier, it is the first "electronic" car I have owned so have gone through a steep learning curve, the 110 is so basic in comparison but would never want to part with it
As far as I am aware the heater plugs operation is linked to the coolant temperature

Mine has done it for 70k miles. Before and after a new set of injectors. I disconnected the vac hose from my EGR years ago but the misfire was already present then. I find that it is most commonly on light throttle on dual carriageways. It's is particularly annoying when using cruise control and the car is semi-coasting down an incline. I take the @Nodge68 approach though and ignore it, particularly in absence of a conclusive reason for it occuring.