Engine Performance problem
1983 BMW 535i 6 cyl Two Wheel Drive Manual 172k miles

car stalls occasionally.3 times in same spot about 1 mile from work on way home. Turns over but no start. starts after about five minutes, or with ether. Have recently done: new plugs,cap rotor,fuel filter,vacuum hoses,thermostat. Checked coolant temp sensor,coolant temp switch,thermo time switch and idle air stabilizer.put seafoam in tank and air intake. has been running beeter than ever and then this