1995 crown vic p71 intermitten shut down at cruising speed

hi,, my vic just shuts down ,,starts running bodly then shuts done completely. I pull over, shut it off.,,,restart and take off,,,for hours or minutes,,,sometimes I need to re-start it several times to get the smooth idle and can rev it up and go. does not over heat but have noticed the temp gauge starts to bounce and go up a little , that's when it about to shut down. ambient temp seems to affect too. made trip to gulf coast,,when it got over 50 degrees or so ,,started to act up.have replaced fuel filter, tps, my gas mileage this trip was half what it usually is...now that I am back in Michigan it runs like a champ...... HELP ME PLEASE

Have you had it scanned? Without a code from the computer, it would be hard to trace down the problem.

that is next on my list.. advance auto said too old to scan. can't even locate the iac,,not where all the diagrams show it to be. been looking at the throttle body trying to find even a wire that would plug into it,,,,it must be on the back of the throttle body near the firewall,,worst possible place,,of course just my luck. went ahead and got a new fuel pump relay.

have had trouble with the lcm... no heater fan,or turn signals or high beams. on my trip I had to hot wire the heater fan so I wouldn't freeze,,,and the turn signals work just fine. ran a line to a fuse that was only hot when the key was on,,,good to go. already installed a floor mounted dimmer switch,,if I could just get this shutting down problem taken care of.........I really like this car..especially for road trips to Biloxi miss.