Land Rover Repair: stalling engine, throttle position sensor, land rover discovery

Question
1998 Land Rover Discovery

After my engine is warmed-up (10 min or so) my engine seems to stall until speeds above 40 mph is reached.  The problem is most noticable in the heat of the summer (humidty) and when the a/c is on.  The problem is not so noticable when the a/c is off.  

I have replace spark plugs and wires, replace auxillary fans, had rad. flushed, verified the visc.fan is in operating condition, change fuel filter and treated gas with gas treatment.

My Disco has 149K miles please help.  

Answer
Hi Rudy,

sounds like the TPS (throttle position sensor) or IAC (idle air control).  Remote problem could be the MAF but the fact that you see no problems at higher speeds has me think about your engine at low idles.

I would suspect this first as I have had experience with this before.

Best of luck,

JohnMc