Hello all

My father has a Kia Sedona ( Not my cup of tea but he likes it) its a 2.9 Diesel automatic. I drove it today for the first time and it has a strange fault as follows

Starts straight away everytime, sounds ok, drives as it should and pull very well etc, all of a sudden it seems to drop its revs as though somebody has turned the engine off.

No lights come on the dash board and if you move the throttle slightly it comes alive again and it runs fine, it seems to happen between 40-55mph 2000 rpm ish.

I drove it over 140 miles today and it happen 8 times, doesnt stop breakdown or anything and as said if you put your foot down a bit more off it goes again no problem, 70 mph plus on the motorway today no problem at that speed.

Apart from the fault it drives fine, good mpg and has only done 52000m from new.

Any ideas would be great

Mick

I'm confused, around 2000 revs it drops the revs in a diesel with an auto box? Is it not just going into overdrive? Or have I miss understood the question? Giving it more throttle would knock it out of over drive, and at faster speeds you'd obviously still need more revs.

They still have overdrive?

Sounds more like it's cutting out and touching the throttle is getting the fuel back in. I persume there's a drop in speed too not just revs otherwise the overdrive explanation makes sense

I presume it is drive by wire It sounds like a throttle pedal pot fault ?

[Edited on 31/12/12 by britishtrident]

If you don't move the throttle what happens, does it coast to a halt and does the engine actually cut out ?

Code reader with live data would be useful (you could see whats happening when the problem occurs) it may even pick up a 'pending code'

Had a new shape Clio that did a similar thing but only when cold, by reviewing the data you could see that the graph for the TPS/Throttle body was all over the place and they are a known fault on these.

No it is not an overdrive type fault.

If you hold your foot in the same position when it does it, the revs drop down to about 1000rpm and the car starts to slow down, there is a noticible jolt like somebody has dabbed the brake pedal slightly or the engine has cut out.

It seems to cut the revs back to tickover and then if you move the throttle slightly it picks up agian, when it isnt doing it,it drives fine.

It has got a TPS and that was my thought, i am just gathering the opinion of you chaps before shelling out wasted money.

Thanks for your replies any other ideas please let me know.

Mick

Have the throtle position sender checked, alternatively just try to stick to 70 everywhere)