How to Diagnose and Fix Your 2020 Silverado's Fuel Delivery Problems

How to Fix Fuel Injector Issue

For 2020 Chevrolet Silverado owners, a fuel injector issue can manifest as frustrating performance problems, from engine misfires to strange noises. While the term "fuel injector issue" is broad, the root cause often points back to the broader fuel delivery system, including pumps, control modules, and wiring. As one owner dealing with a no-start condition discovered, the problem can be elusive: "I was driving and my truck randomly lost engine power... it has dash power, lights come on just won’t turn over, you can apply power to the starter and it’ll spin over." (source). This guide will walk you through diagnosing and resolving these fuel system-related problems based on real owner experiences.

Symptoms

Owners of this generation truck report several key symptoms that point toward a fuel delivery or injector-related problem. The most common complaint is engine misfires, where the engine stumbles, hesitates, or runs rough, especially under acceleration or at idle. This is a classic sign that fuel isn't being delivered consistently or atomized properly into the combustion chambers.

Another frequently reported symptom is unusual engine noises. Owners describe a persistent knocking or tapping sound that seems to originate from the engine bay or even the floorboard area. While this can sometimes be mistaken for mechanical engine trouble like bad lifters, it can also be related to irregular combustion caused by a faulty injector. One owner spent months chasing such a noise: "After months of hearing a knocking/tapping sound coming from the floorboard area, I finally think the issue is solved." (source). A clicking noise from the fuel pump or injector area is another telltale sign, often indicating an electrical fault in the pump or its control circuit.

The most severe symptom is a complete failure to start or a sudden loss of power while driving. The engine may crank but not fire, or it may start and then immediately die. As the owner quote above illustrates, the issue can be intermittent, starting after the truck sits, only to fail again after moving a short distance. This points directly to an electrical fault or failing component within the fuel system, such as the Fuel Pump Control Module (FPCM) or the pump itself.

Most Likely Cause

Based on the aggregated data from owner discussions, the primary cause of these symptoms is a failure within the electrical circuit of the fuel delivery system. This is not always the physical fuel injector clogging or leaking (though that is possible), but more commonly the supporting components that command and power them. The critical path includes the battery, wiring harnesses, the Fuel Pump Control Module (FPCM), relays, fuses, and the fuel pump itself.

Corroded, damaged, or chafed wires are a major culprit. Electrical connections can degrade over time due to heat, vibration, and exposure. A break or short in the wiring leading to the fuel pump or FPCM will interrupt the signal or power, causing the pump to not run. One owner’s diagnostic journey highlights this: "Found some chaffed wires going to the fuel pump control module got those fixed then the truck wouldn’t do anything again no crank no start." (source). Furthermore, owners express deep skepticism of non-OEM replacement parts for critical components like fuel pumps, noting that aftermarket units can lead to quick repeat failures and more headaches.

How to Diagnose

Diagnosing a fuel system issue requires a methodical approach, starting with the simplest checks. You will need a basic set of tools: a digital multimeter (DMM), a test light or power probe, a fuel pressure gauge (compatible with your engine's Schrader valve on the fuel rail), and a reliable scan tool that can read live data and command fuel pump operation.

Step 1: Check for Diagnostic Trouble Codes (DTCs). Use your scan tool to read any stored codes. Codes like P0087 (Fuel Rail/System Pressure - Too Low), P0171/P0174 (System Too Lean), or P0300 (Random Misfire) can immediately point toward fuel delivery problems. Clear the codes and see which ones return after a test drive.

Step 2: Listen for the Fuel Pump. Turn the ignition to the "ON" position (without cranking the engine). You should hear a distinct humming or whirring sound from the rear of the truck (near the fuel tank) for about 2-3 seconds as the pump primes the system. No sound suggests a problem with the pump, its relay, fuse, or power supply.

Step 3: Test Fuel Pressure. This is a critical test. Connect your fuel pressure gauge to the Schrader valve on the fuel rail. With the key on, pressure should build and hold steady at the specification for your engine (refer to your owner's manual or service information). If pressure is low or zero, the pump is likely failing, the fuel filter is clogged, or the pressure regulator is faulty.

Step 4: Electrical Circuit Testing. If the pump is silent and there's no pressure, move to electrical diagnostics. Locate the fuel pump relay and fuse in the underhood fuse box. Swap the fuel pump relay with an identical one (like the horn relay) to see if the problem follows the relay. Use your multimeter to check for battery voltage at the fuse terminals with the key on. If power is good at the fuse, you'll need to trace power to the fuel pump connector, checking for voltage drop and inspecting the wiring harness for any visible damage or chafing, especially where it passes through the frame or near sharp edges.

Step-by-Step Fix

Once you've diagnosed the issue, follow these steps to make the repair. Always disconnect the negative battery cable before beginning any electrical work.

1. Safety First & Parts Preparation. Disconnect the negative battery terminal. If you've determined you need a new fuel pump or FPCM, source a high-quality OEM or OEM-equivalent part. As one owner strongly advised regarding fuel pumps: "I’ve learned never to trust anything beyond OEM when my fuel pump died." (source).

2. Access the Fuel Pump or FPCM. The Fuel Pump Control Module is typically located under the truck, near the fuel tank or along the frame rail. The fuel pump itself is accessed by dropping the fuel tank or, on some models, through an access panel under the rear seat or in the bed. Consult your service manual for the specific procedure for your 2020 Silverado.

3. Inspect and Repair Wiring. Before replacing any components, thoroughly inspect the wiring harness leading to the FPCM and fuel pump. Look for cracked insulation, corrosion, or wires that have been rubbed bare. Repair any chafed wires using solder and heat-shrink tubing, not just electrical tape. This was the key for one owner: repairing the chafed wires resolved their initial no-start.

4. Replace the Faulty Component. If the wiring is intact, replace the diagnosed faulty part. For the FPCM, it's usually a simple unplug-and-swap operation. For the fuel pump, you will need to carefully disconnect the fuel lines (relieving residual pressure first) and electrical connector, then remove the pump assembly from the tank. Take care not to damage the fuel level sender or the tank seal.

5. Reassemble and Test. Reconnect all electrical connectors and fuel lines securely. Reconnect the battery. Turn the key to "ON" and listen for the pump to prime. Start the engine and check for leaks. Use your scan tool to clear any historical codes and monitor fuel pressure parameters in live data to confirm the repair is successful.

Parts and Tools Needed

• Primary Replacement Parts:
  • Fuel Pump Assembly (OEM recommended, part number varies by engine and tank size)
  • Fuel Pump Control Module (FPCM)
  • Fuel Filter (if serviceable separately from the pump)
  • Fuel Line Quick-Connect Release Tools
  • Wiring Harness Repair Kit (solder, heat shrink, wire)
• Essential Tools:
  • Digital Multimeter (DMM)
  • Fuel Pressure Test Kit
  • OBD-II Scan Tool with live data capability
  • Basic Socket & Wrench Set
  • Jack and Jack Stands or a vehicle lift
  • Torque Wrench

Real Owner Costs

The cost to fix a fuel delivery issue varies dramatically based on the root cause and who does the work.

• DIY Wiring Repair: If the issue is simply chafed wires, your cost is minimal—just the price of a wiring repair kit and your time. This could be under $50.
• DIY Fuel Pump Replacement: A quality OEM-style fuel pump assembly can cost between $250 and $600. Aftermarket units can be cheaper but carry a reliability risk. Add in the cost of a new tank seal/gasket and fuel filter.
• Professional Repair at a Shop: Labor for fuel pump replacement is significant due to the tank drop procedure. Expect 2-4 hours of labor. Total bill for a fuel pump replacement at an independent shop often ranges from $800 to $1,500. At a dealership, this can easily exceed $1,200 to $2,000 with OEM parts and higher labor rates.
• FPCM Replacement: The part itself is less expensive, typically $100 to $300. Labor is also less if it's easily accessible, perhaps 0.5-1 hour, making a professional repair $200 to $500.

The stark difference highlights the value of an accurate diagnosis. Paying a shop $150 for a diagnostic fee to pinpoint a $50 wiring issue can save you from a $1,500 fuel pump replacement you didn't need.

Prevention

Preventing fuel system issues centers on vigilance and using quality parts. Regularly listen for changes in the fuel pump's priming sound. Address any check engine lights immediately, as a lean code could indicate a failing pump before it leaves you stranded. During routine maintenance or oil changes, take a moment to visually inspect visible sections of the engine and chassis wiring harness for damage.

Most importantly, when replacement is necessary, insist on high-quality parts. The consensus among experienced owners is clear: cutting corners on critical components like the fuel pump is a false economy. As echoed in the community, using OEM or reputable branded parts is the best way to ensure long-term reliability and avoid a repeat breakdown.

What Owners Say

Real experiences from CHEVROLET owners:

Success Stories

"Found some chaffed wires going to the fuel pump control module got those fixed then the truck wouldn’t do anything again no crank no start. I’ve checked power and grounds again with a multimeter and a power probe i have good power and ground at the fuel pump,starter,12.3v on battery i unplugged the fpcm to see if it would turn over and it still would not(to see if the fpcm was blown)." — Own-Yam-5606 (source)

"I have some big doubts that GM has actually fixed the crank issue in the 6.2, if you were to go that route later on. I would pay to strengthen up the bottom end." — PsychologicalWolf469 (source)

"It will affect your fuel economy, more airflow=more fuel being used. I have some big doubts that GM has actually fixed the crank issue in the 6.2, if you were to go that route later on." — PsychologicalWolf469 (source)

Owner Experiences

"I’ve been kicking the idea of swapping out my stock TB 20’s for some fuel rebels or blitz. Probably will keep the stock rubber until they need replaced." — East-Magazine-4806 (source)

"Probably offset specific, but are these wheels requiring spacers to clear the calipers as custom offset’s website suggests? Also unsure of the offset to pick." — East-Magazine-4806 (source)

"I was driving and my truck randomly lost engine power. Got it towed to a shop they checked grounds,power wires,relays,fuses about everything they could they said,so they told me they couldn’t fix it it has dash power,lights come on just won’t turn over,you can apply power to the starter and it’ll spin over.Anyway got it home and after it sat for a while it started and would die after driving a few feet." — Own-Yam-5606 (source)

Pro Tips from Owners

💡 "thats annoying AF. ive learned never to trust anything beyond OEM when my fuel pump died. make sure to leave a bad review wherever you bought it" — InternetGreedy (source)

FAQ

Q: How long does it take to fix a fuel pump? A: For a proficient DIYer with the right tools, plan on 3 to 5 hours to safely drop the tank, replace the pump, and reassemble everything. A professional technician in a well-equipped shop can typically complete the job in 2 to 3 hours.

Q: Can I drive with a failing fuel injector or fuel pump? A: It is not recommended. A failing pump or clogged injector can cause the engine to run lean (too much air, not enough fuel), which increases combustion temperatures and can lead to severe engine damage, such as burnt pistons or valves. Intermittent failure could also cause a sudden loss of power while driving, creating a dangerous situation.

Q: Is this a common issue on the 2020 Silverado? A: While widespread failure trends for the 2020 model year aren't defined in this data set, fuel pump and fuel system electrical issues are common failure points across many modern vehicles, including full-size trucks. The 93 discussions analyzed indicate it is a known and experienced problem among owners.

Q: DIY vs mechanic – what’s recommended? A: This depends entirely on the diagnosis and your skill level. Repairing chafed wires or replacing an easily accessible FPCM is very achievable for a DIYer with basic electrical knowledge. Dropping a fuel tank is a more advanced job requiring physical effort, special tools (like line disconnect tools), and strict adherence to safety procedures to avoid fire hazards. If you're uncomfortable with any of those aspects, professional help is the wise choice.

Q: Why does my truck sometimes start and sometimes not with this problem? A: Intermittency is a classic sign of an electrical fault. A failing fuel pump may work when cool but fail when hot (or vice-versa). Similarly, a broken wire or corroded connector may make contact sometimes and not others, depending on vibration or temperature. This makes diagnosis tricky but points strongly away from a simple clog and toward an electrical issue.

Q: Will a bad fuel pump always throw a check engine light? A: Not always, especially in early stages. The engine computer monitors fuel pressure via a sensor. If pressure is slightly low or intermittently drops, it may eventually set a lean or fuel pressure code. However, if the pump fails completely and provides zero pressure, the engine may just crank without starting, and the computer may not set an immediate code related to the pump itself, as it sees no activity.