Mr. Baker, I am most grateful for your advice. I am not member JenMon and did not create the thread. I simply joined it with my own problem so as not to start a new conversation on the same subject. You are correct, I have the dual carb model with mechanical fuel pump in the engine compartment to the rear of the distributor and valve cover. However, what I find confusing is the Haynes Manual for "Honda Civic 1984 thru 1991 - All Models". The first attached image taken from the Haynes Manual is of the above-referenced mechanical pump in the engine compartment, which is described in section titled "Carbureted Models". Then, in the next section, which refers to "Fuel-Injected Models", Haynes shows electrical connections to a pump mounted in the fuel tank. My car also has these connections, which is why I assumed that a fuel system relay must be present! If I am correct, the EC series was the one Honda hoped win over the European market; perhaps it wanted to offer the possibility of conversion to fuel injection?