Getting gas to the fuel injectors but they're not spraying.
Oct 11, 2020 at 4:48 PM
Fuel Injectors not working properly
1988 GMC S15
JASONL77
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Good morning,
The injectors are controlled by the engine ECM. When the ECM sees a crank signal or the engine is running, it will command the injectors to flow fuel.
https://www.2carpros.com/articles/car-cranks-but-wont-start
Do you have spark when you crank the engine?
https://www.2carpros.com/articles/how-to-test-an-ignition-system
The most common failure is the ECM for this. I attached a picture and procedure for you.
Roy
THIS PROCEDURE HAS BEEN UPDATED BY TSB # 88-42, dated 9/87
Some replacement ECM's may come with a replacement PROM already installed in them. If this situation occurs, remove prom from old ECM and install in rebuilt ECM.
When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure.
1. Disconnect battery ground cable.
2. Locate ECM on passenger side under the instrument panel hush panel. (see figure 1.).
3. Remove ECM mounting hardware.
4. Remove ECM from passenger compartment.
5. Reverse procedure to install.
The injectors are controlled by the engine ECM. When the ECM sees a crank signal or the engine is running, it will command the injectors to flow fuel.
https://www.2carpros.com/articles/car-cranks-but-wont-start
Do you have spark when you crank the engine?
https://www.2carpros.com/articles/how-to-test-an-ignition-system
The most common failure is the ECM for this. I attached a picture and procedure for you.
Roy
THIS PROCEDURE HAS BEEN UPDATED BY TSB # 88-42, dated 9/87
Some replacement ECM's may come with a replacement PROM already installed in them. If this situation occurs, remove prom from old ECM and install in rebuilt ECM.
When replacing a production ECM with a service ECM, transfer the broadcast code and production number from the production unit to the service unit. Also, during replacement, the PROM, and if equipped, the CALPAK must be removed from the ECM being replaced and transferred to the new unit. Refer to "PROM, REPLACE" and "CALPAK, REPLACE" for procedure.
1. Disconnect battery ground cable.
2. Locate ECM on passenger side under the instrument panel hush panel. (see figure 1.).
3. Remove ECM mounting hardware.
4. Remove ECM from passenger compartment.
5. Reverse procedure to install.
Image (Click to enlarge)
Oct 13, 2020 at 8:21 AM