Power loss after starting. TD5 Disco

Hi all, new to LZ.
I have an 02 Disco TD5 auto. When I start it either from cold or hot it has very little power, acceleration is ridiculously poor and will rev till 3000 till it changes as speed it so slow. I either have to rev it higher up to about 4000 and let it drop which sometimes works, or just wait and all of a sudden, after about 30sec-2mins it’s fine.
I can/could hear the fuel pump whining, it’s now been changed, no no difference)
The tell tail sign is when the rev counter will drop about 2mm to 1000 rpm and I can hear the fuel pump whine change note and go higher. From then on it’s fine and drives no problem till I start it again.

Any ideas?

Thanks.

Have you checked that the turbo is free to spin.

brianp38dse said:

Have you checked that the turbo is free to spin.

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No, will do in the morning. Are you saying it could struggle to spin on start up but when it gets going all ok? As it works fine once it’s going.

Will check tomorrow.

Thank you.

Yes just that and it could be the noise you here as well. turbos should spin freely .

brianp38dse said:

Yes just that and it could be the noise you here as well. turbos should spin freely .

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The noise is defiantly the fuel pump. But will still check turbo tomorrow.

brianp38dse said:

Yes just that and it could be the noise you here as well. turbos should spin freely .

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Thank you

1. Unplug the MAF and drive it so to see how it goes, if it's better you need a new one
2. make sure that the wastegate is not stuck
3. EGR is still on?

Hi if the maf fails it can cause this, also unplugging it can too but give it a go and unplug it

When my auto box is low on ATF, it behaves a bit like this, until what ATF is in it heats up and then flows properly around the box.
So you might want to check it.
If you do not know how to do this, then get it running, make sure the handbrake is fully on, move it into each gear and leave it in each gear for 3 secs or so, return it to neutral, and, with the engine still running, get under and check the gear box level. The rest is obvious. I may not be quite accurate about this as usually I do this with wifey on the gears and, once its running remove the plug, wait till she has done the above then fill it until it runs a steady stream out.

Apparently, if you have deleted the EGR, you don't need a MAF.....
So just unplug it. It's pointless anyway...

Bobdog said:

Apparently, if you have deleted the EGR, you don't need a MAF.....
So just unplug it. It's pointless anyway...

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Not sure that's true. Despite having de EGRd my truck, the bad MAF really did the performance and consumption no favours at all. After an expensive replacement, it goes much better. but others on here will have something to tell you about this.

Bobdog said:

Apparently, if you have deleted the EGR, you don't need a MAF.....
So just unplug it. It's pointless anyway...

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That better hadn't be true after I spent good money on a proper LR one a few months ago.

Bobdog said:

Apparently, if you have deleted the EGR, you don't need a MAF.....
So just unplug it. It's pointless anyway...

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This doesn't make sense anyway because if the engine doesn't know how much air is being drawn in, then how will it know how much doozil to inject?

Thanks for all of your advice, I think it is the M

......MAF sensor. I’ve unplugged it, I still does the problem but only for about 5 seconds rather than a few mins so will get that replaced. And you are right, it haemorrhages fuel.

Thanks everyone

Shimsteriom said:

This doesn't make sense anyway because if the engine doesn't know how much air is being drawn in, then how will it know how much doozil to inject?

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in the main fueling is decided by your right foot, with a diesel theres no throttle butter fly so you get the same full cylinder of air regardless of fuel delivered ,obviously at peak power is restricted by the amount of air available which is were turbos come in and add even more air, all your sensors etc just fine tune to ensure emissions are as ideal as possible

Stanleysteamer said:

Not sure that's true. Despite having de EGRd my truck, the bad MAF really did the performance and consumption no favours at all. After an expensive replacement, it goes much better. but others on here will have something to tell you about this.

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Ask @wammers .... he'll tell you, diesel engines don't need a MAF sensor unless they have an EGR....

jamesmartin said:

in the main fueling is decided by your right foot, with a diesel theres no throttle butter fly so you get the same full cylinder of air regardless of fuel delivered ,obviously at peak power is restricted by the amount of air available which is were turbos come in and add even more air, all your sensors etc just fine tune to ensure emissions are as ideal as possible

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Ahh... so in a non-turbo diesel, the air is constant, so fuelling is decided by the 'right foot'. However in a turbo diesel, the air flow is variable so there needs to be a way to measure it to adjust fuelling accordingly - i.e. a MAF sensor?....

Bobdog said:

Ask @wammers .... he'll tell you, diesel engines don't need a MAF sensor unless they have an EGR....

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Are you joking or just a bit ''tricky" , mr @wammers knows everything about classic diesel engines and nothing about electronic management of EUI/PD engines IMO ... or are you bored ? knock yourself out with the whole thread and others https://www.landyzone.co.uk/land-rover/td5-maf.315630/page-2 ... i'll not say more what ever happens that's a promise

sierrafery said:

Are you joking or just a bit ''tricky" , mr @wammers knows everything about classic diesel engines and nothing about electronic management of EUI/PD engines IMO ... or are you bored ? knock yourself out with the whole thread and others https://www.landyzone.co.uk/land-rover/td5-maf.315630/page-2 ... i'll not say more what ever happens that's a promise

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Oh I've read it....
I can see both sides of the argument but I haven't seen conclusive evidence either way, as to whether you need a MAF if you have deleted the EGR, or not...