26
May
If your MAF (mass air flow sensor) is faulty and you see a significant improvement when you disconnect the MAF why can you not just leave it disconnected?
Disconnecting the MAF forces your ECU to use a default MAF value. This may result in a much more responsive engine if the MAF is faulty however, it could result in poor fuel economy. Hence it is not a good idea to just run with the MAF disconnected.
Hi Sue,
I have an issue with my Freelander 1 TD4, before I explain my problem….the Freelander has done 115,000 miles I brought her a couple of years ago with full service history the car was well cared for, since owning her I have serviced her properly with genuine oils and filters, I’ve changed the oils in the drive train etc and upgrade the Crank Case Breather Filter, changed the Turbo Vent Filter and changed the Fuel filter in the rear wheel arch and put the Renault 4 Thermostat mod in so she runs at full temp.
My problem is with the MAF plugged in the car starts fine but idles a little rough and struggles to rev past about 2000 revs, the throttle response is poor and it’s almost undriveable under load I.e out on the open road, she smokes a little like she’s over fuelling or unburnt fuel, so far I have replaced the MAF with a genuine Bosch and then another to make sure the first was not faulty, I’ve changed so far the Air Temp Sensor, Boost Pressure Sensor, all four glow plugs with Bosch ones and the seals on the HP Fuel Pump Regulator the one in the engine end fuel pump, I’ve also cleaned the EGR Valve and Air Box, I’ve check for leaks on all pipe work as heard this was a common problem, i have suction in the small pipes I have no fault codes or Engine Management Lights on.
Have you seen this problem before can you suggest anything I may have missed please ??
Hi Steve,
We have seen this issue before, when the original Bosch MAF has a fault any subsequent Bosch MAFs do not work. Generally there are two ways of dealing with this, one is to reprogram the ECU and the other is to fit a Pierberg MAF with Synergy Ron box.
All the best,
Sue
0780 9575 421
Thanks So much for your reply, this may help you and others….
This morning I chased what I thought was air getting into the fuel system, the HP Fuel Pump engine end was hissing with LP pump running with ignition on engine not running, so I checked the LP fuel pump under the driver side rear wheel arch, it’s looked a little damp, for now I have done away with the water trap and made new pipes and replaced the connectors no leaks upon checking. Bleed up via ignition on off half a dozen times, still hissing, the I changed the little rubber pipes on the HP Pump feed and return, bleed system again, that’s when the real problem showed it’s face, the HP pump is leaking fuel from The ‘Cylinder Head’ the bit with the plunger under it with four torx holding it in place. Recon Fuel Pump on the way.
I have brought a Ron box, I feel I’m chasing a problem that been there since I purchased the car about two years ago, everything I touch has been taken apart before I guess looking for the problem I have been encountering, my biggest gripe is that upon inspection of the MAF that came out it had been messed with so it would not work., the ECU is not reading the fuel rail pressure and maybe any sensor that controls the running of the engine and when I replaced the MAF to one that worked it didn’t like it and wouldn’t run.
My best guess is it’s been running with a faulty HP fuel pump and Broken MAF for 10.000 miles in ‘Default Mode’’ in my ownership slowly getting worse until I started to investigate the problem and like everyone go through the motions of locating the real problem after fixing everyone else’s bodges and attempts to fix the problem which they did not.
Well here’s to getting my hands dirty and changing the HP Fuel Pump.
I will keep you posted if this solves the problem which it should fingers crossed I don’t find anymore issues,
Kind Regards and once again thank you for your reply, I look forward to fitting the Ron Box once this issue is solved.
Update, recon H.P fuel pump fitted today, as the one on the car was leaking, no change in performance but at least that’s another problem of the list, Two options now I think number one fit The Ron Box and fingers crossed it cures it, number two have the ECU reset so that it unlearns what it has already learnt and then it might read the Bosch MAF again.
I have recently purchased a Synergy 2 and Peirburg MAF kit I fitted the unit to my 2006 FL1 TD4 manual and the old girl was transformed – absolutely love it actually like driving a diesel after 2 years of an unplugged maf. (I’d replaced with another bosch years before and it never worked so left it unplugged)
Two weeks later I have developed an issue and having read everything on your website and scoured landyzone I can’t see anything that fits. Would you be so kind to look over my notes below and pass comment or ideas as to what the issue may be?
I did find an intake vacuum leak between MAF and duct to turbo with a snapped clip – I’ve fixed that did 50 miles over 2 journeys, again like a rocket and then the next morning it was back surging.
The issue is that the car surges in normal driving (no power for 3-4 seconds regardless of throttle position, power for 3-4 seconds repeated unless very low throttle demand) becoming more noticeable under load. It occurs around 1750ish rpm to 2500 ISH rpm.
If I give it the WOT and floor it, keeping it high in the rev range through gears it goes and has no issues and will hold 70mph + no problem. If I drop down to 50mph for instance in 5th gear I can’t get back up to speed because of the surging and have to give it some welly in 4th.
My confusion is that it doesn’t seem to be a fuel pressure issue as it runs great at WOT, boost obviously works again with WOT. Runs fine with MAF unplugged which I know doesn’t tell you much.
The engines had;
Rebuilt injectors at a BOSCH approved centre.
New LP fuel pump and filters.
New air filter
New temperature sensor
New boost hoses
Cyclone filter
Turbo breather filter
Boost pressure solenoid a few years back.
Probably missed other bits… I’ve had it 5 years and done 70k
Any thoughts on things to check or change will be gladly received, having driven it on level 6 it’s such a pleasure to drive I’m even more determined to get it working. I’ve left the battery disconnected tonight to see if it drives fine after a reset. Otherwise it’s MAF off till I can suss it out.
Thanks in advance,
Alex
Hi Alex,
Thank you for getting in touch, so sorry to hear of your problems.
The first thing to try would be changing to the uprated fuel rail pressure sensor wiring loom and maybe changing the Pierburg MAF sensor for the Bosch.
Please let us know how you get on.
All the best,
Sam
Dear Sue,
Sometime back my Freelander 1 TD4 was diagnosed to have a “Airflow Meter sensor malfunction” I have now changed the sensor with a new one, the problems remains the same, no power and engine keeps reving up/down …. but the diagnosis message is now “Air flow meter sensor malfunction – HFM5 short circuit to battery positive +ve”
Any idea ??
Cheers,
Jameel
Hello Jameel,
Thank you for your message.
Nobert said to try disconnecting the sensor, if you still experience the same problems then the wiring loom will need to be checked by an auto electrician.
Please let us know how you get on and if I can offer any further help.
All the best,
Sam
Thanks so much for your quick response, I will revert post checking with my mechanic.
You are most welcome Jameel
Hi,
Hope you can help. Yhe problem I have is on a Freelander 1 td4 2005.
No power at low revs then picks up to drive as normal after it eventually gets to 2100or about. No error codes for MAF but does show slight issue with injector 3, drives perfectly with MAF disconnected so don’t think this is the problem. Garage is taking the car back on Monday but they have said they are at a loss as, surely 2 MAFs can’t be faulty but the car runs perfectly when disconnected.
Hi Tony,
If the Freelander runs without issue when the MAF is unplugged then the issue is most likely with the MAF. We have known when a MAF goes wrong and is replaced with another Bosch MAF that it does not operate correctly (not sure why but we have seen it happen a number of times). In these instances it is usually better to replace it with a Pierberg MAF with Synergy Ron box, this gives the added benefit of being able to set it for either fuel economy or performance (or somewhere in between) and is not much more expensive than the Bosch MAF.
Have the garage checked the small vacuum pipes for any splits or degradation?
All the best,
Sue
0780 9575 421
Hello,
couple of weeks ago I bought an LR Freelander 2, 2.2 td4, auto gearbox. Everything is ok with the car, but I have a very poor fuel consumption, eg: driving smooth in town I get 16 l/100km (18 mpg average). Can you give me some hints, on how to check, or should I consider this as normal?
Thank you in advance!
Hi Adrian,
That does not sound normal. What condition are your tyres in? Are they all the same make, model, size, tread depth remaining and air pressure? If you have a difference in the tyres it could be that the 4×4 is kicking in when it shouldn’t, putting a strain on the drivetrain and giving you a low mpg.
All the best,
Sue
+44 780 9575 421
I’ve been told I may have a MAG sensor problem, when I accelerate from a standing start I often get a jolt? Like the power cuts out momentarily then carries on as normal, this isn’t under hard acceleration either.
Hi Pete,
My apologies for the delay in responding but we have been on vacation and only returned to work today.
Is your Freelander a Freelander 1 TD4 2.0 diesel? If so, then try unplugging the MAF and see if it behaves any better. If it does then the MAF will be the issue and should be changed. A better alternative to replacing the MAF with another Bosch MAF is to fit a Peirburg MAF with a Synergy Ron box.
All the best,
Sue
+44-780-9575-421
Hi Sue, I have recently bought a 2005 td4 freelander and it runs rough at low reva but seems smooth above 2000 revs. The thing is I’ve changed the fuel filter and pump so I am testing the maf to see if it could be that. When I unplug the maf it makes no difference what so ever, but it does not bring the eml on, any ideas? Any help gratefully received thanks Ian
Hi Ian,
If unplugging the MAF made no difference then the MAF is likely to be your issue (if the MAF was working unplugging it would cause a change in performance). Please be aware that with the Freelander 1 TD4 replacing the MAF with the original Bosch MAF does not always work, a better solution can be to replace it with the Pierburg MAF with a Synergy Ron box, this has the added advantage of you being able to adjust the settings for performance or economy and it does tend to get rid of the flat spot at around 2,000 rpm that they tend to have.
All the best,
Sue
0780 9575 421
Thanks Sue, do you have a link for that part?
Hi Ian,
The link is https://www.tuning-diesels.co.uk/synergy-2/.
All the best,
Sue
0780 9575 421
I had an issue with MAF sensor and was mistakenly thinking the ambient air temperature to be MAF. Called up Sue just for help, not just she corrected me but gave me valuable tips how to resolve the issues of smoking, etc. Can’t thank her enough!
It was a pleasure to be of help Uttam.
All the best,
Sue
Driving a freelander 1 td 4 2004 unplugging the the maf sensor car revs up but smoke black pug it back not rev up no power and intercooler pipes not getting hard
Hi Benny,
This sounds like you need to replace your MAF – it is worth considering changing this for the Ron Box with Pierburg MAF, they tend to be more reliable than the original Bosch MAF’s and give you the ability to set it to your preferences re performance and economy.
It also sounds like you may have a split in one of your intercooler pipes so you should check these.
All the best,
Sue
0780 9575 421