Stalling Range Rover.....
Here is some helpfull info from the RRRemedies web site;
Its pretty detailed, but makes interesting reading,
A common problem on Range Rover Classics is an annoying tendency to stall when you come to a stop after a long run. Kevan Wiser repports his procedure for fixing this periodically recurring problem.
1) Be certain the flame trap isn't blocked--remove it and check the "mesh wad" It just unscrews from the top-front of the PS valve cover.
2) Check the T-piece that connects the vacuum hoses going to the plenum--it's the obvious one central-front behind the distributor.
3) Clean the stepper-motor plunger and seat. this is easy to do is usually what corrects the problem for Kevan. He uses "brake cleaner" and a toothbrush to clean the plunger assembly making sure to clean the head that has to mate w/ the seat. Then, he uses a rag dipped in brake cleaner to clean the seat itself. He has read that others have used a bit of white grease to lube the plunger, but he always just gives it a shot of what ever WD40 - like substance is handy. For more on the care and feeding of this pesky and temperamental component, see the section on the idle air bypass valve/stepper motor above.
Joel Mahoney experienced similar symptoms on his LWB. It would stall out at stop signs and red lights and also to bog down (and register horrible gas mileage!) when driving on the highway. Both of these occurences were fairly intermitant, which made it difficult to diagnose. After replacing many other components he noticed that the problem seemed to worsen over bumpy roads, indicating some kind of wiring issue. He went into the engine and started pulling on various wires, and found the lead from the harness to the ignition module pulled right out! After re-wiring the connection with new butt-connectors, and tightening them down properly, the vehicle has run without a stutter ever since!
Greg Olma reports that cold stalls may be your coolant sensor or the wiring for it. He states "My 89 would stall and be hard to start all the time before complete warm up. The sensor is telling the ecu to lean the mix out too soon. When warm it was fine. I took to two foot driving to keep up the the idle speed when stopped at lights, etc. I noticed that Saab 900 and VW Golfs from the late '80s had an identicle looking sensor and plug. My plug was cracked, so I pulled a Saab and a VW set up and Voila! it worked perfectly, No stalling and tough starting when cold again".
Larry Michelon reports that a dirty Mass Air Flow (MAF) sensor has caused stalling upon startup, refusal to idle when hot and excessive fuel consumption on both his RR Classic and his 97 Discovery. He first discovered it on his Disco when it generated an OBD-II fault code indicating "exceeding max air percentage". Cleaning the sensor solved the problem. On his Classic, he zeroed in on the MAF sensor incorrect air mixture message after his attempts to fix the stalling problem by changing idle air control valve did not work. During his investigations he accidentally disconnected the MAF sensor, and found that it made little difference -- leading him to suspect it might be inoperative. After removing the snap ring and screen, he gave its insides a good lean by injecting the following into the sensor hole: WD-40, diluted simple green, water, and low pressure air (the latter two to flush out any residual lubricant). If he was doing it again he would use tuner cleaner (the TV stuff available at Radio Shack), but would still recommend flushing out the lubricant/cleaner.
Hot Stalling while running on the highway has been reported by a couple of owners to be due to a bad coil. Howard Lefkowitz had such a problem on his 92 model several years ago. After plugs, points, distributor cap, plug wires etc. he noticed a white substance coming out of the coil. "New coil and problem fixed." It is interesting to compare this experience with that of Walter Gates on his 4.0 which had stuff exuding from the coil (see 4.0/4.6 coil page).
James Howard reported another source of stalling problems that turned up on his father's 93 model -- while driving, the engine would occasionally "load up", then quit running. Most of the time you could turn the switch off and then restart it while rolling along at 40+ mph, after which the engine ran perfectly. The problem was often associated with a code 69 "Gear selector switch or circuit" on the underseat diagnostic code readout box. After replacing the switch to no avail, he took it to the dealer. Their tech knew exactly what it was, because he had seen it before. There is some wiring for the gearbox circuit up in the fender that can get damaged. When that happens, an incorrect signal is given to the computer, which confuses it, and causes the running problems and stalling.