1990 Ford F-150 Fuel Injector

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  • 1990 FORD F-150

Engine Mechanical problem
1990 Ford F150 6 cyl Four Wheel Drive Automatic 78,000 miles

The fuel injector keeps running afer the truck is shut off. It usually would stop after a few minute. The last time keep running until the battery was drained.
What could be the problem fuel injector or the relay and is it possible I could fix it my self. I usually don't work on my cars, but don't have the money for a trip to the shop.

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have the same problem?
Thursday, January 22nd, 2009 AT 12:18 PM

1 Reply

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Hello .. thanks for the donation .. much appreciated

All the injectors recieve power from and ground from ECA(electronic control assembly) basically it's the cars computer .. for injectors to be staying energized @ key off the wiring through the ECA would have to be bad .. power is supplied to injectors @ key ON ..through the ECA and a seperate pulsed ground is supplied to injectors for enegizing @ firing time (ground on to inject fuel ground off to stop injection)are you sure it's an injector draining battery ? let me know ..

During system operation, ECA transmits electrical reference signals to engine sensors and analyzes return signals to determine engine operating conditions. If a sensor or actuator fails, ECA initiates an alternative strategy, allowing vehicle to maintain driveability. This strategy is called Failure Mode Effects Management (FMEM).
The CHECK ENGINE light will illuminate and remain on whenever FMEM is in operation. The ECA, overriding failed component with a FMEM substitute operation value, continues to monitor failed sensor. Should signals from faulty sensor return to within operational limits, ECA will cancel FMEM control and resume control based on sensor signals


Each cylinder has a solenoid-operated injector which sprays fuel toward back of each intake valve. ECA controls pulse width or time each injector is energized.
Fuel injectors meter and atomize fuel delivered to engine. Each injector receives battery voltage through ignition switch circuit. The ECA controlled ground circuit completes circuit and energize injector.
Injector bodies consist of solenoid-actuated pintle and needle valve assembly. Injector flow orifice is fixed and fuel pressure at injector tip is constant. Atomizing spray is obtained by shape of pintle.


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Thursday, January 22nd, 2009 AT 3:56 PM

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