Losing Throttle...Help!

Evening members,

I have a 2002 110 TD5. Recently, when I have been accelerating through the gears, usually at the 3rd or 4th gear change, I will suddenly lose throttle/acceleration and the catalytic converter warning light will come on the dashboard. I still have power and the engine is running, but when I put my foot down on the accelerator, nothing happens. I then have to either pull over and turn off and then on the engine, or, if I can't pull over, stop and start the engine on the move.

Similarily, when i'm doing 60mph down the motorway and I go over a bump or a pothole, the vehicle will suddenly slow and down and acclerate again (in a jolt like motion), almost like i've taken my foot off the pedal and then depressed it again, even though I haven't. And on some occassions, if I go over a bump at that speed, the vehicle will jolt and the catalytic converter warning light comes on again and I have no throttle, like the scenario above, which as you can imagine is terryfing on a motorway. It happened four times on the way from Cardiff to Wycombe. It was serviced and MOT'd in July by a LR specialist garage who I trust.

Any suggestions would be greatly appreciated!

Many thanks,
James

It sounds very much like you have a loose connection somewhere in the TPS loom/connections of .. but it could be the TPS itself..

Any codes ?

Haven't got any codes.

I think it could be that or it could be something to do with the Turbo as I'm getting a lot of turbo lag at the moment too.

Think you better get codes read by a proper reader [ not a cheap fleabay job] Guessing the problem and than playing "parts darts" is not the way.
May well be an ECU problem, pretty common with older TD5's Have a look at " www.ecutesting.comland-roverdefender-discovery-td5 " for more info

The other problem that TD5s have is the wiring loom itself. Intermittent problems with the accelerator response sometimes happen as a result of this. The insulation on the wires gets brittle as do the copper conductors. In this case, the wiring between the accelerator pedal and the ECU deteriorates. The tendency to go off when you go over a bump suggests this - mine first showed up when I went over some potholes. I've had this, as has @KISSMYAURA
I'm intrigued that you've got a catalytic converter warning light. I've not seen one of these on a TD5. However, this kind of fault does tend to put the engine warning light on. Is that what you mean?

jjpparker said:

Haven't got any codes.

I think it could be that or it could be something to do with the Turbo as I'm getting a lot of turbo lag at the moment too.

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If you think it is a turbo issue, the waste gate have a habit of seizing on a td5. So might be worth checking it is freely moving. But your symptoms and the warning lights do point more towards and electrical issue than a mechanical one.

Yes, my apologies. It is turbo/engine warning light that is showing up on the dashboard. If I'm honest, the more I've looked into it, the more I think it's turbo related. I hopefully will get it in the garage this week and let you know the outcome. Expensive as it may be!!!!

Remove the engine cover and the turbo heat shield, (or bodge it like the picture below and just cut around it) to access the waste gate actuator and waste gate.



Unclip the waste gate actuator arm, the little spring clip will end up halfway across the drive it you are not carful, and check the pivot on the turbo (right hand side of the pic) is free to move. It is sprung so will need pliers or similar. If it is not put some penetrating oil on it and work it back and forth until you get a smooth full range of movement. Both myself and a friend have had this seize despite using the vehicles regularly.

When my actuator seized I just got surging at higher throttle opening

headintheclouds said:

When my actuator seized I just got surging at higher throttle opening

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Mine and friend both had the same symptoms which was the turbo just never felt like it kicked in.

check relays under the seat i had one loose once that gave me trouble like that