Land Rover Repair: 1995 disco idle problem, throttle position sensor, mass air flow

Question
1995 V81 Disco
When car is fisrt started will idle and run correctly. Once the car is driven for a short while and has warmed up the idling of the car becomes erratic and lacks power, thus making the car undrivable.
would you be able to point me in some direction as to were to look. My thoughts lead to maybe a problem in the distributor area.

hope you can assist

Rod Parker

Answer
Hi Rodney,

could be the throttle position sensor (TPS) or idle air control valve.  Rarely but possible, it could be engine temperature sensor, mass air flow (MAF), coil or even the ECU.

First make sure your '95 is tuned properly.  New plugs, wires, distributor cap and rotor.  These are all necessary and should be changed every two years anyway.  They can also give you rough idle problems if they are at fault.  The engine system adjust according to the ignition sensors so it's best to have them in top condition.

Rare but possible, the coil and amplifier module (found on the distributor) have been known to fail.  Heat is the main culprit in causing these two components to fail.  The coil and spark amplifier module are expensive parts...$800 each from the dealer.

If it's not your plugs or wires, I would start looking at the TPS, IAC, MAF and others.  These are more expensive components to replace and require some mechanical expertise.

I hope this helps you go in the right direction,

JohnMc