5 x Fuel Pump Failure (Chevrolet Blazer) – Fixes

Fuel Pump Failure (Chevrolet Blazer)

In this article, we will delve into the topic of fuel pump failure in the Chevrolet Blazer, exploring the challenges and their corresponding solutions. So, without further ado, let’s begin.

1. Difficulty Starting Due to Fuel Pump Malfunction (2000 Chevrolet S-10 Blazer)

Let’s assume you have recently purchased a 2000 Chevrolet S-10 Blazer, which initially had issues running on all six cylinders. After replacing the spark plugs, spark plug wires, and distributor, the engine now runs on all six cylinders.

However, the fuel pump doesn’t seem to be functioning, making it impossible to start the vehicle. The engine starts perfectly when using starter fluid, but the fuel pump doesn’t turn on despite trying a new relay and jumping the relay.

Diagnosing and Fixing the Fuel Pump Issue in 2000 Chevrolet S-10 Blazer

To diagnose and resolve the fuel pump issue, follow these steps:

  1. Confirm that there’s no fuel pressure using a fuel pressure gauge.
  2. Use a digital multimeter to check for 12V at the fuel pump priming connector for a few seconds when the key is turned on. The priming tab is located in the UHFB in the engine compartment.
  3. Charge the battery, remove the surface charge by turning on the headlights for 20 seconds, and ensure that the resting voltage is 12.6V at the battery. Then, recheck the voltage at the priming tab.
  4. If the voltage is adequate at the priming tab, proceed to measure the voltage and ground at the fuel pump connector under the truck. Back probing the power and ground with everything connected allows you to see the voltage under the pump load.

After these steps, if you still face issues, consider charging the battery and rechecking the voltage. Sometimes, lightly tapping the gas tank may temporarily resolve a fuel pump issue, but a more permanent solution will require further investigation.

Once the issue has been identified and resolved, your 2000 Chevrolet S-10 Blazer should be able to start and run smoothly without the need for starter fluid. Remember, it is crucial to consult a qualified technician if you are unsure about any of the steps in the diagnostic process.

2. Unable to Start Due to Fuel Pump Failure (Chevy S10 Pickup)

Let’s say you were using your Chevy S10 pickup, parked it, and when you attempted to restart it, the engine wouldn’t start. The fuel pump doesn’t activate when the ignition key is turned to start the engine.

Additionally, you’ve replaced the fuel pump and checked the fuses and relay under the hood, but there’s still no power to the fuel pump, and the gauges inside are not working, except for lighting up.

Troubleshooting Steps for Chevy S10 Pickup Fuel Pump Issue

  1. Inspect the ignition control module: Check the small black box under the key switch, known as the ignition control module. Tapping on it might restore power to the fuel pump and gauges. If this works, consider replacing the ignition control module with a new one.
  2. Access the fuel pump: If necessary, remove the bolts at the back end of the truck and, with the help of some friends, lift it away to access the fuel pump.
  3. Check for a blown fuse or defective pump relay: Inspect the fuses and pump relay for any defects. If they’re in good condition, proceed to the next step.
  4. Verify power at the sending unit connector: Check for power at the sending unit connector. If there’s power, proceed to step 5. If there’s no power, probe the electrical circuit for an open circuit or damage.
  5. Inspect the fuel pump connections: Remove the fuel pump from the tank and examine the connections going to the pump. If the connections are in good condition, replace the fuel pump.

By following these troubleshooting steps, you should be able to identify and resolve the fuel pump issue in your Chevy S10 pickup.

3. 1999 Blazer Fails to Start Due to Non-Functioning Fuel Pump (Chevrolet S10 Blazer)

In this situation, a 1999 Chevrolet S10 Blazer with a 4.3L engine has issues starting. The fuel pump doesn’t seem to run when the key is turned on, and there is no pressure at the fuel gauge connection. The owner has already replaced the fuel pump, fuel filter, and spark plugs, but the problem persists.

Identify Wiring Issues and Verify Power to Fuel Pump

  1. Verify fuel pressure with a gauge before looking into other issues. There should be no interaction between the oil pressure sending unit and the fuel pump on newer models.
  2. Ensure the new pump runs when the key is turned on. If not, verify power to the pump and check the voltage at the relay.
  3. Check for proper voltage at the terminal that corresponds with Pin 30 on the relay. It should be supplied with battery voltage through the ECM B fuse (20A).
  4. If necessary, run continuity tests to measure the resistance between the terminal corresponding with pin 87 and pin B in the fuel pump connector. Additionally, do a continuity test to ground with the relay removed.
  5. If you find a wiring problem with improper voltage, monitor the voltage across the pump wires with it hooked up to the pump. This will help identify if there is an issue with the ground connection.

In this case, it appears that there might be a problem with the fuse block assembly, leading to an unreliable connection. You may need to consult with an experienced electrician or replace the fuse block to resolve the issue.

4. Restoring Fuel Pump Function in 1988 Blazer S10 4×4 2.8L Due to Power Loss

You own a 1988 Blazer S10 4×4 2.8L, which has been running smoothly for two years. Recently, someone broke into your vehicle, opened the hood, and stole the battery, cutting out the wires and connections in the process. After replacing the damaged wires and connections, your Blazer now turns over but won’t fire up.

When using starter fluid in the throttle body, the engine starts but doesn’t stay running. You don’t hear the fuel pump activating when turning the key on, and you have already checked and replaced the ECMB fuse.

Troubleshooting Steps for Restoring Fuel Pump Function in 1988 Blazer S10 4×4 2.8L

  1. Replace the fuel pump relay: Find the three relays side-by-side on the driver side rail and replace the appropriate relay (the front-most one). If you’re unsure, you can try swapping the relays around to see if other functions, like the A/C or horn, stop working, indicating a faulty relay.
  2. Bypass the fuel pump relay: Locate the pink or orange wire in the same area as the relays, which serves as a fuel pump relay bypass. Connect it to a 12V power source from your battery and check if the pump starts working.
  3. Check the fuel pump ground: Inspect the fuel pump ground located near the rear of the tank, attached to the rear frame crossmember. Clean the ground connection and see if the fuel pump starts working.
  4. Replace the fuel filter: Install a new fuel filter, which is either located on the frame under the driver side or on the engine itself. Consult your vehicle manual for the specific location and installation instructions.
  5. Utilize line wrenches: When working with fuel lines, use line wrenches to avoid rounding off the line fittings. This can make a significant difference in the ease of installation and removal of fuel line components.

If the problem persists after following these steps, consider consulting a qualified technician for further assistance.

5. Troubleshooting a Non-Working Fuel Pump in a 1994 S10

Your 1994 S10 5-speed truck wouldn’t start after leaving it parked at the airport. Suspecting a fuel pump issue, you replaced the fuel pump and strainer, but it still wouldn’t turn on when you turned the key. After swapping the fuel pump relay with the horn or A/C relay, you still had no luck.

Testing for Fuel Pump Functionality in a 1994 S10

Check the fuse: Before testing anything else, ensure that the fuel pump fuse is not blown.

Use a volt meter or 12-volt test light: With the ignition on, check the wires leading to the fuel pump to determine if there is any power. If there is no power, backtrack to the fuel pump relay and fuse.

Connect a grounding wire: Connect a grounding wire from the top of the gas tank’s fuel port to the truck’s frame to ground the fuel pump. This may help activate the fuel pump.

Replace the alternator: If you experience a seized alternator, replace it with a new one. Remember to also check the fuel pump fuse and relay to ensure that they are working correctly.

Remember, if you are not comfortable with troubleshooting the fuel pump, it is recommended that you consult a qualified technician.

Final Words

In conclusion, fuel pump issues can cause a variety of problems with Chevrolet Blazer and S10 models, leading to difficulty starting or inability to start the vehicle altogether. However, by following specific troubleshooting steps, such as checking fuses and relays, testing for power, and replacing components as necessary, it is possible to identify and resolve these issues. If you are unsure about any steps in the diagnostic process, it is recommended to consult a qualified technician.

Imran Khan

Imran Khan is a car enthusiast with a technical background, who shares valuable insights and tips on fixing common car problems in an accessible way through his blog. He aims to connect with other car enthusiasts and help car owners take control of their own maintenance and repairs, reducing reliance on expensive mechanics.

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