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> Fuel injection not working, 73 2 liter
smveril
post Nov 3 2019, 01:28 PM
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I have a 73 2 liter that I am near the end of the restoration.

We are trying to get the car to run. The engine is rebuilt, it has a Bosley fuel injection harness.

We pulled two injectors and we saw no fuel flow. The fuel pump runs and we have fuel pressure. We then removed the ECU and checked the pin outs on the ECU cable per Paul Andres schematic. One thing we found was the start signal from the ignition switch was 10.5 volts. It should be greater than 12 volts (pin 18 and ground).

What could cause the low voltage to the ECU?

Thanks,
Mike
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jcd914
post Nov 4 2019, 10:21 PM
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QUOTE(smveril @ Nov 3 2019, 11:28 AM) *

One thing we found was the start signal from the ignition switch was 10.5 volts. It should be greater than 12 volts (pin 18 and ground).


The power to the ECU from the starter circuit is so the ECU will power up the fuel pump while the engine is being cranked over. The ECU probably does not need the full 12 volts in order to power the fuel pump.
Does the fuel pump run while cranking the engine?

The starter circuit is notorious for low voltage to the starter.
Many people have added relays or the Ford start solnoid to get the starter to engage. I have never heard anyone having an issue with the low voltage to the ECU from this same circuit.
The ECU gets battery voltage it uses for operation from a different circuit bia the power supply relay on the engine compartment relay panel.

Check fuel pressure.
Check the 3 ground wires at the top rear of the engine case bolt.
Check for voltage pulses at the injectors, a mood light is the simplest way to check this.
Check the connector for injector points in distributor, needs to be tight.

Jim




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