Fuel injectors not working?

BROKERRON07

MEMBER
1991 CHEVROLET S-10
6 CYL
2WD
MANUAL
140,000 MILES

Truck will run if fuel is poured directly into carb. When poured-in fuel burns up, truck goes dead. There is power to both injectors and the electric fuel-pump is making-up after each start attempt. There is power on both terminals of both injectors. Replaced one injector(w/new one) truck still won't run.

1 Reply

JDL

CERTIFIED MECHANIC
16,099 POSTS

On TBI systems, you can usually see the injector spray pattern, with the engine cranking, if the injectors are pulsing.

The injectors won't pulse without an rpm signal, you need to check for an injector pulse, with the engine cranking. You might take the connector loose from the injector and use an L.E.D. Testlite between the two terminals on the connector for the wiring harness. With the engine cranking, does the lite pulse on and off or brighten and dim. You also could use a noid lite. One wire is B+ and the other ground

Are there any trouble codes, how's the fuel pressure?

If you saw voltage on both wires at one injector plug, was the connector plugged in or not? If no pulse is detected I would replace the ignition pickup and module or see if you have spark to help confirm the failure.