I have a 1991 Toyota MR2 that will not start.
The EFI fuse is for fuel components, and for powering up the ecu. There is a lot on that circuitry. The 15 amp fuse, is also the power for the EFI relay. If this relay is without the power from that fuse, you probably won't have the fuel pump working, and the ecu won't be fully powered up.
Check the fuse again to see if it blew out again. If it did, you will have to trace the circuits for a short. Also, the EFI fuse gets power from the 40 amp AM2 fuse, so if the EFI fuse has power to it, the AM2 fuse is okay.
If I were you, I would test and check all fuses in all fuse/relay boxes under the hood. checking fuses is easy with a cheap test light. With the key in ON, every fuse on the car has power to it. So you clip tester light to ground (use neg. batt'y post), and then use test light probe into the little slot on the top end of a fuse. You do not have to take fuse out to visually inspect.
On the top end of all fuses are 2 little slots (one at each end of fuse) that is open to the metal strip inside. So you turn key to ON, then probe one end of the fuse. The test light should light up. Even a blown fuse will light up tester on one end of the fuse. Now to test the fuse itself, use the probe and touch into both ends of the fuse. A good fuse will light the tester on both ends of the fuse. A blown fuse will only light up one end of the fuse-the metal strip has blown so no power on both ends of the fuse, SEE?
And by using the test light, you also verify that power is getting to
the fuse. It is easy, and you are on the way to becoming an automotive electrician. Next, you need to buy and use a multi-meter, for automotive uses buy a digital volt-ohm meter (DVOM), which is what most multi-meters really are. And you don't have to buy an expensive one. I have a Sears Craftsman DVOM, about 20 years old, and it only cost like $30.