03 TD5 No low down power

Hi folk
Have a TD5 which runs and sounds well except there is little power low down. Once past 2500 rpm alls fine and acceleratiion /pulling is fine.
If I hit a hill at 50mph in top it would just die and even a change down won't help unless its above 2500rpm then all goes good.
I believe there are 2 sensors on the trottle - could one of them cause this sort of problem.
Recent work done for info:
New pump, filter, regulator, injector seals/washers, crank sensor

Any ideas????

UnPlug your MAF sensor and report back. If it drives better then you need a new one, £65-70 for an OEM part (VDO Siemens). Had exactly the same fault as you and new MAF fixed it. Have a search on the forums for more on the subject of cleaning the MAP sensor too as this can get gunked up if you still have your EGR valve fitted.

This would appear to be the problem. With MAF disconnected I certainly seem to have better pulling at low revs. I assume that with the MAF diconnected the ECU is on a base programme which would mean that full power is still not available. However, very happy to be moving forward

Thanks

You've found the problem then, good news.

If you're resigned to buying a replacement anyway then you could try very very carefully cleaning the filaments in the old one with a suitable solvent. I've used carb cleaner before and a cotton bud. Don't apply any pressure to the filaments, just gently wipe the bud over top and bottom of both and repeat several times, there's also a reflective mirror like surface at the base of the bit where the filaments protrude from, I've no idea if that's important but mine was covered in dusty muck so I cleaned that until it was shiny too, don't use the solvent on this though as it might melt the plastic!

In all honesty though cleaning only put off the inevitable for a couple of months, I've just fitted a new VDO Siemens one myself and it's better than its been in the year I've had he car!

And yes, you're spot on about the ecu using a stored baseline value, it won't drive as well as having a working MAF but will be a lot better than having a knackered one connected, you'll loose a couple of mpg with no MAF as it'll be over fuelling at times I suspect and might be a little smokier, that in itself could cause problems if left disconnected for a long time. Overfueling might also damage the engine/injectors long term too so best bite the bullet and get the new MAF ordered. Reading around, a lot of people have said that the £30 ones on eBAy are false economy as they don't last and also don't work as well if you've got a remapped or chipped ecu (which I have), my advice is to go for the OEM VDU Siemens part.

All good info.

When I took the MAF out it was easy to see it was at fault as one of the 2 small filiments was already gone

Ahhh well bad luck, but at least you know it definitely needs replacing then.

I'd just like to reply to this to thank you folks for the MAF suggestion and maybe bring it to the attention of others again.

The 2003 Td5 I've just bought had exactly the symptoms described by the OP and when I unplugged the MAF, the improvement was dramatic.

I put a new one in (£125.00 inc VAT from a LR dealer) and I have to say I'm struggling to detect the difference between new and disconnected but getting rid of the old broken one has made the world of difference.

Thanks all.

I also just did a new Siemens MAF in my '03 as well after having it disconnected for some time. It now seems to have a slightly less power down low but in exchange it has more power all around, especially at higher revs. Overall it's much more drivable.

I also did an EGR delete and K&N air filter. Overall my Td5 full of power now, whereas before it was a high-revving tractor...