OVP was the cause of my hot start problem, but coolant temp sensor caused an erratic idle problem I once had.
Also, a faulty wiring harness shorting at the EGR was a culprit for poor driving performance. This was replaced free, as a service bulletin indicated that there was a harness problem with some W124 models.
I also had the plug wires replaced, and found that the spark plugs were gapped too wide, so car missed during load conditions. Put in new plugs that were correctly gapped.
Also replaced fuel filter (which you didn't mention in your replacement parts list).
Check the fuse at the top of the OVP as well...it will still cause big problems if blown...
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car