No injector Pulse

CARSDAVE84

MEMBER
1994 GMC SIERRA
5.7L
V8
4WD
AUTOMATIC
169,000 MILES

No fuel being delivered to cylinders. Fuel system including throttle body has been replaced, noid light is not showing any pulse. Ignition module has been replaced as well. I am wondering what else I can check for. Fuses and relays are good as well.

Monday, September 24th, 2018 AT 1:38 PM

3 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon.

Do you have spark? For the injectors to fire, the ECM needs to see a crank signal or rpm reading.

Do you have power to the injectors? Fuse box feeds power to the injectors and the ECM quad drives ground the injector for fuel to flow.

I attached a diagram for you to view. Check the fuse listed for power on both sides.

Roy

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Monday, September 24th, 2018 AT 2:16 PM

CARSDAVE84

MEMBER
2 POSTS

Thank you for the response. I checked the connections and fuse link with volt meter, I am getting good power on both sides. However, I am not getting spark as well.

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Monday, September 24th, 2018 AT 4:27 PM

ASEMASTER6371

MECHANIC
52,797 POSTS

Okay, check the cap and rotor. Check you ignition module as well. Common failure for no spark.

Once you get spark, fuel should return.

Roy

https://www.2carpros.com/articles/how-to-test-an-ignition-system

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Monday, September 24th, 2018 AT 4:33 PM