Collin is most likely correct. I had almost the exact same issues that you had but I knew the main wire harness was good (I replaced in just 2 years earlier). It ended out being both fuel pumps when bad. On the bench when I tested out the fuel pumps they only worked maybe 40% of the time I applied current to them. I had to "deal" with this issue for 5 months (and two tows). I did replace the OVP and a host of other things before replacing the two expensive bosch pumps. I recall my wagon working well 1-3 weeks stints between the hiccups arose. Keep an eye on it...