Pacerdonfl

RECENTLY BOUGHT, 140K MILES, HAD DEALER 100K SERVICE. HAVEN'T DRIVEN IT MUCH, BUT FOR A FEW DAYS WOULD GO ALL DAY OR SOMETIMES LESS THEN BEGIN TO STALL. WOULD CYCLE FROM NICE, SMOOTH IDLE TO JUST BEFORE STALLING, THEN BOUNCE BACK UP TO NICE IDLE, THEN ALMOST STALL.....IT WOULD DO THIS A NUMBER OF TIMES AND FINALLY STALL/QUIT. I COULD START IT RIGHT UP AND IT WOULD DO THE SAME THING, CYCLING FROM NICE RUNNING TO ALMOST QUITTING, THEN RUNNING NICELY AND FINALLY QUIT. I COULD ALWAYS START IT BACK UP. AS OF YESTERDAY IT WOULD START, AND ONLY RUN FOR A MINUTE OR LESS, THEN CYCLE DOWN-UP-DOWN-UP AND QUIT. ALWAYS STARTS UP EASILY AGAIN, BUT STALLS W/IN 30 SEC TO A MINUTE. I HAVE ANOTHER WORKING 91 LS400 - HAVE SWAPPED FUEL PUMP RESISTOR, FUEL PUMP RELAY AND INSTALLED A NEW FUEL FILTER. STILL THE SAME - STARTS NICE AND QUICKLY, RUNS SWEETLY FOR 30 SECONDS TO A MINUTE AND A HALF, THEN SLOWLY DROPS RPM. SOMETIMES WILL GET TO 100 RPM THEN BOUNCE BACK UP TO NORMAL, THEN DO THAT CYCLING FOR 2-5 TIMES AND THEN FINALLY DIES. ALWAYS WILL START RIGHT BACK UP.... ARRRRGGGGHHHHHHH!

Thank you very much for your time and suggestions, Randall. I'll try the trouble light thing. I will also check the operating pressures on each side of the compressor.... Is there a source for diagrams/pictures to show where "sensing" items are, i.e. - the compressor pressure switch. Also, I've also been reading that maybe there is a temperature sensor that could be faulty and telling the compressor to dis-engage? Also, what do you make of the driver-side electric fan spinning very slowly??? Thank much! /Don

I have had a 91 LS400 for a little over a year, and starting to drive it more these days. Over the year, the A/C has "flashed-out" and stopped cooling very intermittently. I'm sure it's not the compressor freezing up, or it would not begin again to run properly, as it does. There is no (obvious) rhyme/reason when it cuts out and begins blinking, but it does that maybe once a week or two. Later or next day, works and cools perfectly. I replaced the clutch relay and still goes out now and then. It was converted to 134 a couple of years ago by previous owner (father). The electric fan on the drivers's side runs very slowly???? Any ideas would be greatly appreciated.... Thank you, /Don