Mitsubishi Repair: 92 LeBaron 3.0 Mitzi stumble,power loss, crank angle sensor, highway speed

Question
Hi, 92 Lebaron 3.0 Mitzi automatic, Car starts and runs fine until 60-70 mph. At highway speed I feel an intermittant loss of power, or stumble. This goes away with a surge at an idle in drive, car will run fine for a short while then this will come back, Replaced rotor,cap, plugs and wires. Air and fuel filters, fuel pump seems to be pumping with good pressure. no idiot lights coming on, my mechanic cant find anything wrong, but I wonder if i will make it to work somedays it never stalls just runs flat. any help is most appreciated. Regards-Rob

Answer
Rob,
It sounds as if a fuel injector may be failing to operate temporarily.  You most likely would not see any check engine light if your injector shuts down.  Also, your crank angle sensor may be sensing your timing is off, so it retards the timing enough to cause your engine to struggle.  You may need to have your timing belt replaced.

All these systems are tied to your car's computer.  You may want to have your car's computer checked to see if there is any damage.  It's a known issue on Mitsubishi computers between 1989-1994 were manufacturered with under-rated capacitors that would leak over time.  Have the computer checked for damage.
Good luck!