Freelander 1 MAF defect and rail pressure too low?

mbrokof · Mar 18, 2022

Hi All,

as mentioned in another thread I've run some tests as the car drives not very well. Two days ago on the test the MAF didn't look very good as it didn't provide the values requested. Yesterday I unplugged the MAF and tested again and the values looked much better as per the below sheet. Will put the original one in to see how it behaves otherwise will get a new one, though that one was from end of 2018.

Over both days test and before the rail pressure seems to behave really odd as I'd have expected the values to constantly increase with speed, but somehow it goes up and down. Would it mean that the fuel pressure sensor needs change or is it the sealing ring on the regulator?

KR
Matthias

hd3 · Mar 18, 2022

from your prev.

The car's driving sluggish again and fuel consumption went up to 9.2l/100km or 30.70mpg if I calculated it correctly on mixed. If I go through it looks if there might be some issue with HP pump, but not sure.

is the car still running odd .. down on power .. even with maf unplugged ???

re. fluctuating pressure ..
is that while you keep the go-pedal down fairly hard ??
or while cruising at speed ?
[ i couldn't get thru scanning multiple photos of scanner data
[ to view tp data / speed / fuel pressure ..

when were the fuel filter last changed ??
has the car sat for any extended period .. i.e. months ?

re. down on mpg ..
maybe remember to keep an eye on oil levels ..
to rule in .. or out .. hp.pump leakage into the crankcase
[ a faulty maf .. can cause mpg issues .. though supposedly rare
[ but .. so will an unplugged maf

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mbrokof · Mar 19, 2022

hd3 said:
from your prev.

is the car still running odd .. down on power .. even with maf unplugged ???

re. fluctuating pressure ..
is that while you keep the go-pedal down fairly hard ??
or while cruising at speed ?
[ i couldn't get thru scanning multiple photos of scanner data
[ to view tp data / speed / fuel pressure ..

when were the fuel filter last changed ??
has the car sat for any extended period .. i.e. months ?

re. down on mpg ..
maybe remember to keep an eye on oil levels ..
to rule in .. or out .. hp.pump leakage into the crankcase
[ a faulty maf .. can cause mpg issues .. though supposedly rare
[ but .. so will an unplugged maf

`````````````````````````````````````````````````````````

Morning hd3,

thank you for your response. With the MAF unplugged it improved definitely. I measured yesterday, but somehow it didn't let me upload the results as pdf. After unplugging it showed more air measured than requested compared to the ups and downs before. Will put in the original today and see how it goes. I couldn't upload the pdf yesterday, below are some pictures from it.
Re the fuel filter that might have been some years now till it last got changed, but not the 60T that are mentioned. Would need to check, but someone from the garage mentioned, that it might help.
The car was standing during lockdown, might have been a year.
The go-pedal I don't use really hard because of the fuel, but when I tried it after the MAF was unplugged to see if there is an improved that showed up on below 17.3. literally the same as before and definitely not like it was before at around 70mph having 125MPa. I found an old one with the old reader and it showed about 146TKPa. At 40mph it still shows 110000KPa, which is odd compared to the new one. Will check with it to see if something has changed.
Do you mean the hp leaking to get the sealing changed? https://www.ebay.co.uk/itm/183199123287

mbrokof · Mar 20, 2022

Put on the old MAF today and found on vacuum hose from rear of the reservoir to the t-piece split on both while i tried to change the one to the turbo. Something has improved, but uphill is still weak and somehow the turbo seems to over-rev or starting too early. Couldn‘t get the hose onto the turbo solenoid end properly , so kept the old one on for now.

PS About the oil, have checked it a couple of times. It'd be due for a change, but as there is an oil smell all the time after driving, there seems something wrong. The undertray was covered, but I think that's from the gearbox as they said they had it opened when checking the IRD. Cleaned it to see, but with engine oil it's now from last week only half between lower and upper marking. Had it asked in the garage already about two years ago and like usual nothing wrong.

Am wondering if there is a blockage to the turbo on one of the hoses.

4Bee4Bee · Mar 22, 2022

I had all sorts of problems with my TD4 after leaving it standing idle for a year during lockdown. I was getting strange MAF readings, that actually seemed to decrease as more throttle was applied. Thinking it was a faulty MAF I put a new one in. But had exactly the same dodgy readings. After much faffing around I replaced the Fuel Pressure Harness with the modified one, and put a new sensor in. That alone solved the strange MAF readings I was getting I'm sure. I did change the regulator over too, but I'm certain it was the sensor / harness that solved the issue, as I later had to put the old regulator with new rings back in to cure an overrun problem that had developed, which changing back did solve.

There wasn't any obvious green corrosion on my pressure sensor. But given its age and the fact it had never been replaced made me think it was still worth a shot. Maybe you could try some contact cleaner on it first to see if that make any difference.

Might be worth seeing if you can swap the fuel out too, as if it has been sat there for a year it will be past its best (the downside is it now costs 50% more than it did when you put it in :-( If the filter hasn't been changed in a while, it will be worth doing that too, even though, if you have the under the rear wheel arch version, it's much more PITA job than it should be. But very doable.

mbrokof · Mar 22, 2022

That sounds interesting. When I apply the throttle it comes also up with odd values like 315 yesterday again. I had the pressure sensor checked on Sunday and used a bit of contact spray, but still nothing. It doesn't look green either. I thought for a while if I have such a problem and bought a pressure sensor last year. Having seen hd3's comment I hope it'll fit. According to Febi website it should but is much shorter than the old one. Will check if the plug fits and get one of those harnesses as well.
Hope I change the fuel filter myself. Will read into Haynes again, as last time I couldn't get it sorted. It's the one under the bonnet. It read easy, but wasn't. I was wondering if I'd need to take the battery off to get more space.

Having another trouble as yesterday talked to a neighbour and when he checked the dipstick he said he'd be overfilled which was about a cm above the upper marking. Maybe last time I got something wrong. Was done in a garage and I had before the feeling there would be too much in.

mbrokof · Mar 25, 2022

@4Bee4Bee, sorry got stuck with engine oil when neighbour said it'd be overfilled. Investigating and thinking what to do on another threat. Might need to get the hpp changed not sure if the one would play into the other.

mbrokof · Aug 23, 2022

4Bee4Bee said:
I had all sorts of problems with my TD4 after leaving it standing idle for a year during lockdown. I was getting strange MAF readings, that actually seemed to decrease as more throttle was applied. Thinking it was a faulty MAF I put a new one in. But had exactly the same dodgy readings. After much faffing around I replaced the Fuel Pressure Harness with the modified one, and put a new sensor in. That alone solved the strange MAF readings I was getting I'm sure. I did change the regulator over too, but I'm certain it was the sensor / harness that solved the issue, as I later had to put the old regulator with new rings back in to cure an overrun problem that had developed, which changing back did solve.

There wasn't any obvious green corrosion on my pressure sensor. But given its age and the fact it had never been replaced made me think it was still worth a shot. Maybe you could try some contact cleaner on it first to see if that make any difference.

Might be worth seeing if you can swap the fuel out too, as if it has been sat there for a year it will be past its best (the downside is it now costs 50% more than it did when you put it in :-( If the filter hasn't been changed in a while, it will be worth doing that too, even though, if you have the under the rear wheel arch version, it's much more PITA job than it should be. But very doable.

Which sensor did you use? I have a Febi here which is the same length like the one from LR, but I read lots of things about being to short, not tight and so on. There didn't come a sealing nor that other kind of extension with it.

4Bee4Bee · Aug 23, 2022

Hello,

The sensor I used was one I bought from Craddock, along with the harness upgrade https://www.johncraddockltd.co.uk/l...ator-freelander-td4-and-rrover-3-0-litre.html

From memory, I think it was a Bosch part. It had all the bits necessary to do the job without any leaks. Look at the picture on the Craddock link and see if you have the same.

Follow the instructions on this thread to do the replacement https://www.landyzone.co.uk/land-rover/td4-fuel-pressure-sensor-confusion.203488/

Hope this helps

mbrokof · Aug 27, 2022

Hello,
Thank you for the link. Yes it looks the two parts are missing additional to the sensor. Will get a Bosch one, I guess or ask Febi where they are first.
and thank you for the instructions. Have also printed the bulletin.

Freelander 1 MAF defect and rail pressure too low?

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