This is agonizingly familiar - runs poorly but only intermittently. And the problem only appears when you are driving the car. And it gets better for a while after you replace something.
Other than sympathy, I can offer three low-cost suggestions.
- Spend $18 on the EHA test harness (PN 102-589-04-63-00) and connect it to some long leads to your multi-meter so that you can monitor the current readings while driving. You can verify that the readings are in spec, and observe differences when the car acts up. That may provide a clue to the problem and would at least eliminate mixture correction as a problem.
- Replace all the rubber vacuum connectors
- Run a couple of cans of Techron the system in the gas
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe