I spent about 2 hours trying to diagnose my 'dead fuel pump' one day after swapping the battery in my 1800E. After a very long time, I finally realized that the FI system had a separate power supply wire on the + battery terminal, and it had fallen off. Everything else was working except the fuel injection system. I now know to check that the FI system is powered up before bothering to check anything else downstream. With the key on, you should hear clicking when the throttle is pressed down - the 'accelerator pump' action of the throttle switch firing the injectors. If you don't hear that, then perhaps the FI system as a whole isn't getting power.

There are two relays on the FI system. The 'main' which switches the entire system (presumaby so the computer gets cleaner current directly from the battery terminal, not 'dirty' current from the ignition switch). And a fuel pump relay, so the computer can control the fuel pump with a light weight control circuit. On an 1800E both relays are on the right side of the engine compartment, back beside the better, directly behind the MAP sensor. The front relay is the fuel pump, the back one is the main.

The fuel pump relay is powered through fuse 5 on the main panel. As for the main relay, I almost think there is no fuse on it, although they did stick a little add-on fusebox on later years. But at least on my wiring diagram for my 1800E ('71) they show no fuse. The main relay is triggered from a brown wire leading to the positive terminal of the coil.
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I'm JohnMc, and I approved this message.