where it stands today; where is egr?
Thanks to all for input.
This morning I drove 5 miles into town and it seemed to be running better and better. Idle and acceleration at low rpms are both better but not yet perfect. (Does the engine's computer "learn" as it goes?) I still plan to install the o2 sensor (120 k miles) and a new fuel filter (unknown age), and I think I should clean the egr valve (help--I still can't find it). I read some posts about the ovp relay but got confused--could the ovp be part of the problem too (I'll check its part # tonight)? Other than that, I will buy no more electronic parts.
As to the wiring harness: My plan has been to check and replace the obvious culprits (plugs and plug wires; O2 sensor; fuel filter) before I write the owner of the dealership I bought the car from and beg for a new harness (for free or at a very big discount). The problems are 1) both the service manager and the parts department there have told me they have never heard of this bad wiring harness problem; 2) the dealer is 700 miles away.
3) before I spend my own money on a new harness I need to r&r the serpentine belt and pulleys (cracks on ribs every 1/16 inch) and the driveline (play in ujoint). But that is another topic.
94 E320 Wagon, 170k, totalled in 2006
2002 BMW 525i Wagon, 75k
1991 BMW 318is (two of 'em)