I think the problem has been solved. My battery had multiple dead cells. The guy at the Interstate store said it looked as if the battery was whacked against something. Replaced the battery, drove it for a couple of hours running errands with as many accessories running as I could turn on and no problems as of yet. The only thing I noticed was strain on the engine with the A/C on but that's normal as far as I know.

 

That is good news and a simple fix - we hope.

For the next week or so, measure the battery voltage after shutdown and prior to startup.

Battery voltage should be at least 12.5 VDC. I say that as if the alternator is failing, the zener diodes within can fail closed circuit, (short circuit), rather than open circuit as with most alternators in other vehicles. This short circuit drags the battery down and in the extreme can wreck the battery.

Thanks for the update; we all like to hear how these things progress.

 

I had the same suspicion about the diode. I had the alternator checked and the diode came up as being good. But I'm following your advice. I'm keeping the voltmeter in the car and checking as I go. Thank you so much for all your help.

 

Update... everything was going good for a few days until it happened again! The 3 died twice coming off of a stop light. But this time I payed attention to the tach. It was fluctuating between idle about 600-650 rpm and a little over 1000 rpm (my best guess) as it was dying. Also, the engine was sputtering like it was being choked. I figure it's either no air, no spark or no fuel. I cleaned the throttle body which wasn't very bad. Replaced the throttle body gasket. Cleaned the Mass Airflow Sensor which had some carbon/dirt buildup. Replaced the plugs, all of which had normal wear. Finally I threw in some Techron injector cleaner fueled up and hit the Highway. I drove at a good 70mph clip for a couple hours and presto!!! I've been running smooth, idling great, no hesitation or sputter. I think there was some gunk in one or more of the injectors from cheap gas seeing as how I have no clue what the previous owner put in it. I guess the LR3 is more high maintenance than my wife. I guess that's why she likes it so much.

 

re: I guess the LR3 is more high maintenance than my wife

SWMBO might improve her mood with some suitable alcohol based solvent, with ice.

 

o.k. Here we are again. Everything was going good until I went over a section of asphalt that was cut out and the damned thing died again. A synopsis of events; I drove over a section of pavement that was cut out approximately 24 inches by 10 feet (the width of the street) and just a few inches deep. I rolled over this going about 20 mph and the Rover died. It just cut off like I had turned the ignition off as soon as the front tires passed over. But I still had all electrical i.e. radio, a/c, etc. I came to a stop took the key out of the ignition waited about 30 seconds and restarted without a hitch. I went around the block and did this a few more times going even slower around 10-15 mph and each time same thing. As soon as the front tires hit, the engine turned off. This hasn't happened with speed bumps or potholes or dips in the road just this one particular type of obstacle. I even made a few hard stops in an effort to get the front end to dip and nothing. Is there any connection, sensor, ground connection, computer module in the front end that would cause this? Could there be a relation to the suspension sensors?

 

By the way, I did check the 2 main ground connections from the battery when this whole mess began. They are firm.

 

If you have, set the display to 4x4 info and find a curb about 6" high. One at a time, slowly mount each wheel up onto the curb and back off again. You should see vertical wheel movement on the display for each wheel, or not. Regardless of the results, then do the same on the offending portion of road.

The odds are all is well as I have never heard of an air suspension wiring problem shutting the engine down. Keeping it from starting, yes, but shutting down, no.

I think the problem is some wire touching or almost broken or a connector coming in contact with an upper front wheel arm. As such, remove a front wheel and look about - you may have to remove a wheel liner as well - not easy.

The jpg below shows air suspension connectors hidden under the left front wheel liner. Note the exposed individual conductors.

You may have to have the engine idling as you jostle wires about; if lucky, maybe the engine will shut down.

Also try going across the cut at an angle - the problem may require both wheels to hit at the same time - that would be bad as it means that the problem is any wire somewhere in the front end that is getting moved about. I think one of the electro viscous fan wires could initiate a shutdown as that would suggest to the computers, a cooling system problem and that will shut the engine down.

Also pull that black cover off the top of the engine and see if any wires such as the temperature sensor wires are loose - one guy had a mouse living up there chewing away. A cut or disconnected temperature sensor wire is a no go condition.

 

O.k. I jacked up the Rover and maneuvered, twisted and tugged on every wire and connector in the front end that I could get my hands on. But I couldn't get the thing to die. I did go over that same cut in the road at an angle and that was fine. It seems to only die out when the the front tires hit simultaneously. Do you think jacking up the front wheels while the Rover is on stands would be helpful or do you think I may need impact force to get it to die out. And I did check for damage under that plastic cover and all was fine.

 

I am beginning to wonder if there is a safety system that is acting up - fuel cut out, roll over, that sort of thing. In other words, something in the vehicle is feeling an impact and thinking it is a crash, perhaps? I don't suppose the 4 way flashers come on, or if the doors were locked, that the doors unlock just after hitting the bump? In a good crash, where the air bags go off, the doors are supposed to unlock, the 4 way flashers turn on, and the engine turn off. Well at least you are not doing air bags yet.

If I am correct on it being a safely system thing, then I think that you will have to go to a dealer to get the codes read with specific emphasis on some emergency shut down code being falsely triggered.

There is one more big ground wire, but somehow I doubt it is the problem. Under and across the engine there is a second big ground wire. To find it, you would have to take the engine oil pan skid plate off. It you do look at it, loosen the bolts and then tighten them up, sort of to create a new bond surface.