disco td5 flat spot

hi i have a flat spot on my td5 disco when accelaraiting at 3000 rpm to 3500 rpm and jerkes a lot when doing so. after 3500 rpm clears any ideas ??????

dont rule out that the TD5 is a fly-by-wire using a rheostat mechanisim on the throttle pedal

Hi,
Mine will sometimes do this as well, it revs up to 3000 happily, and if I continue on at about 3200+ it coughs and spluts almost like a petrol misfire !!

Once it gets past about 3500 it's fine and then will rev smoothly up to the rev limiter (not something I do regulalry by the way)

Talking the the main dealer it was their opinion that it's the air flow meter, which is the first 'gadget' in the air intake after the filter box, aparently they are very prone to failure !!!

Haven't got around to changing yte, just keep to a 3000 rev limit, better for fuel mpg anyway !!!!!

battenberg said:

dont rule out that the TD5 is a fly-by-wire using a rheostat mechanisim on the throttle pedal

Click to expand...

Could be, but the intersting thing is that in low range, the throttle re-maps to allow for bumpy terrain (and a jumpy right foot) and it still does the same at 3000 rpm

ive unpluged the air flo metre and still the same that was my first thought but still the same i sprayed a bit of wd40 on the peddal which did seem to be a bit better but has come back so it could be the throttle peddal

Thanks for the tip, never thought of the throttle, I'll give it some attention and see if it changes anything

the question just made me think of scalextrix as a kid and the controler would always get kinda worn at a particular point...

may not be anything to do with it... who knows??
just thinking outside of the box..

Ah . . . maybe i will check the little copper wire brushes underneath to make sure the're making good contact as well then

yeah...good call...and how come I always get the crapy slower car when we play at your house???

Cos mine's the one with the motor outta the Mr's hairdryer in it

(and yours has the double sided sticky tape round the wheels )

use a multi meter on the air flow meter to find GND and a main voltage feed , ,
There is 1 more wire left this is signal out. The middle one if my memory serves me correctly.

Measure from the GND to the signal out and you should have 1.5-2Volts at tickover.
Under hard fast rev you should see 4-4.4Volts, if you only see around 3volts the maf is dead, and this is common the td5.
Unplugging a maf that is only out of calibration and NOT totaly dead normaly dont show any difference.