V6-3.0L,Washed Engine Now Car Won’t Start

Was offered an engine wash as part of a package at the carwash and I obliged. Driving back home (about a mile later) The car started to jerk and it went into limp mode. Flashing Engine light. It crawled to the house. (A quarter mile more) and it hasn't worked since. (3 Months ago) It rolls but doesn't start. Sometimes it starts and then it goes right off. I am in West Africa and these cars aren't common here, so mechanics are a little baffled. They ran codes and it showed misfire in all cylinders. They suggest I change the ECU, which I did and nothing changed. The mechanic says the