95 Town Car Problems

Hello everyone. I have a 1995 LTC I am experencing some electrical issues that I could use help with. First on the INST MPG part of the cluster, it has been jumping up and down intermitelty for about a month. As soon as I start moving for example 6 mph, it will jump to like 45 mpg then 87 slowly making its way to the 99 mark, then as you hit 2nd gear, it will drop down and slowly move upward until 99 or the next gear. The only time it stops is when the cars come to a complete stop. I was told there is a black box called a "GEM" under the dash that controls this. This is the only part of the cluster that is not working correctly. Also, the other problem that I am having is the factory anti-theft. Intermittently I will try to start the car, it will crank but not start. I have to take the key out, open the drivers door, lock and unlock the doors with the key fob close the drivers door, turn the key again, (this time I hear the fuel pump turn on) Then the car will start. I am curious if these problems are connected..... I would appreciate any and all help...

Bryan

I would start by checking the factory grounds are clean and tight. Then buy a years subscription to http:www.alldata.com/ they have good electrical manuals which you will need to check the system out.