I usually post on the W123 page concerning my '82 300TD. I'll ask those of you who are more familiar with W124 chassis to chime in here with some opinions regarding a '93 W124 300E owned by a good friend of mine. His car has 100K on the clock and has had regular maintenance since new but not to the same extent some may recommend.
The car will either stall or go into a "limp home" low power on an intermittent basis. This happens sometimes several times a month or may not occur for months and can occur at either highway speeds, in city driving or at idle. After restarting, the car will perform fine although it may take several restarts to get the car running again.
He states the car has had a tune up within the past year ( he drives maybe 12-15K per year) but has never had a fuel filter change. Someone has suggested to him this condition may stem from a fault in the wiring harness. Tht doesn't seem likely to me unless the W124 has some fault in the harness I am unaware of.
I've suggested he perform another "baseline" tuneup consisting of plugs. plug wires, filters (including fuel filter) and a bottle of Techron followed up with an ounce or so in each tank for the next 2-3 fill ups using only quality gas and see what happens.
Can anyone think of anything else to zero in on here? Appreciate any thoughts you W124 guys might have.