It appears that my 1985 190E has just consumed its third electo-hydraulic actuator in two years: Cold start stumble, no power past 1/4 throttle ( lean-out, backfire, etc). mA current values seem ok, water temp sensor a little pessimistic ( about 1k too high at 20C, system and control pressures spot on. I hate replacing symptoms, so what could be causing this early failure? Also, has anyone ever made their own injector testor?