Land Rover Repair: 89 Rangie overheats; difficult starts hot or cold, land rover range rover, temp guage

Question
Today I come to you in need of help with my Rover.
1989 Land Rover Range Rover  3.9 v8 4 door with awd. Automatic transmission.
VIN#  salhv1241ka343206
I went down through all the rover questions already asked and found helpful info. on some other things I needed as well. There are only two things I question now. #1 is my temp guage shows overheating but when I check the fluid while it is hot it is flowing as normal with no leaks. Is this a faulty gauge?
#2 This vehicle usually fires right up, but recently it had started not wanting to start it would turn over easily but no fire. Sometimes I would try it a couple of times amd them it will go. Or sometimes I wait several hrs and it will start. And it has died twice since this started but fired up immediately after it had died. Then about a week ago I drove it to get gas and it did it again however I have not been able to get it started since. I was turning over easily but my battery has to be jumped noe to get it to turn over still no spark. I have replaced distrib. Cap cleaned as many conections and grounds as I could see. Replaces coil and capacitor( little round metal thing by coil with wire touching the coil the hanes  rovers north calls it a suppressor ibought mine at auto zone they call it a capacitor is that the same thing. I am getting no visible spark from coil. And I tested the air sensor thing on the air breather by bypassing the sensor with paper clips just to give it a unbroken circut but nothing changed. Any help would be awesome. I am in Spencerville ohio 45887 thanks for your time. By the way I am having the exact same problem with mt 87 nissan pathfinder with in 2 weeks of each other what do you make of that.  

Answer
Hi Chad,

could be two unrelated problems.

The first problem could be as simple as a bad thermostat.  It's rare to see a faulty temp guage...I'd replace the thermostat to see if it helps.

The second problem could be your solenoid or ignition switch.  I'd guess the solenoid on your starter.  Make sure the lead wire to your solenoid is clean and free of oil deposits. A saturated wire can prevent the much need power (amps) needed to start your Rangie.  This sounds very much like a problem I was having - until I replaced the solenoid on my starter.

Before you start looking at the coil, address the initial starting problem.  Can you bench test your starter?  You can always pull the starter and have a local parts shop give it a quick bench test.  Maybe Advance Auto could do this for you or the guys at AutoZone.

Once you have the starter removed take a very close look at that lead wire to the starter solenoid;  make sure its clean and not frayed in any way.

Best of luck,

JohnMc