Dear scotty,
I have a 1988 toyota corolla fx16 gts with the 4age engine 240000 miles and a manual transmission and a salvage title. We replaced the water pump on it and syphoned he bad fuel out of the gas tank and put in new fuel. When we tried to start it it would crank but not start. The fuse for the efi system is not blown and has been replaced. I bought the wiring diagram for the car and the wire that goes to the fuel pump isn't getting any power but all the wires that go in the same direction are getting power. We decided that the wire must have been damaged and rented a wire tracer but that ended up being a dead end. If you can help us find out what's wrong with the car I would really appreciate it.
also, after you check the fuel pump fuse and relay like the moderator said, check your wiring diagram for the Circuit Opening Relay (COR). It does the same thing as an inertia switch. Cuts off the fuel pump in case of an accident.
Except is isn't triggered by impact. The relay has 2 coils in it.
1 coil gets energized when the key is in the start position.
After the vehicle is started and starts sucking air through the intake, the 2nd relay coil is energized by a ground provided by the Air Flow Meter Sensor.
I guess the premise being, when the vehicle wrecks and the engine stalls, air will stop being sucked into the intake and the airflow meter will stop providing ground to the COR relay's #2 coil, shutting down the fuel pump.
So, if you have a defective AFM sensor, or a defective COR relay, your fuel pump won't get power.
I think on the 1980's toyota trucks it was located behind the glove box. On the cars it was located near the center bottom of the dash.
Look for these components on your wiring diagram.
The circuit opening relay and the fuses are fine so I guess it's the AFM sensor do you know where that is located
I think your AFM is right at the air intake box.
Your fuel pump won't run unless the ignition is in the "START" (cranking position) or the engine is running.
Makes it hard to test. If you can locate your diagnostic connector (under your hood) you should see this "connector map) on the inside of the cover.
If you jump the B+ socket (Battery voltage) with the FP socket (Fuel Pump) it will bypass the other connections and the fuel pump should run with key in the "ON" position.
Poking around, it seems that a common trouble spot for the fuel pump wiring on your '88 Corolla is where the wires go under the seats. Maybe give that area of the wires a good looking over
You're on the right track. Just keep following your wiring diagram and work your way across the circuit testing each component as you go.
The fuel pump should have a fuse and a relay to supply the power right? Test those next.
