1. Fuel System:
* Fuel Pump: This is the most common culprit for no fuel. Listen carefully near the fuel tank while someone turns the key to the "on" position (don't crank). You should hear a brief whirring sound from the fuel pump. If not, the pump may be faulty, the fuel pump relay is bad, or there's a power or ground issue to the pump. Check the fuse for the fuel pump as well.
* Fuel Filter: A clogged fuel filter will prevent fuel from reaching the engine. Replace it as preventative maintenance, even if it seems fine.
* Fuel Pressure: You'll need a fuel pressure gauge to check the pressure at the fuel rail. The specifications are in your owner's manual or a repair manual for your specific year and engine. Low pressure or no pressure points to pump, filter, or regulator problems.
* Fuel Injectors: While less likely to cause a complete "no fuel" situation, faulty injectors can be tested with a fuel pressure gauge or a noid light.
2. Ignition System (No Spark):
* Ignition Switch: A faulty ignition switch can prevent power from reaching various components, including the ignition system.
* Ignition Coil: Check the coil for cracks or damage. You can also test the coil's primary and secondary resistance with a multimeter (consult a wiring diagram for your specific truck).
* Ignition Control Module (ICM): The ICM is a common failure point in GM vehicles. It's often located near the distributor. These can be tested with a multimeter, but usually require specialized equipment or replacing as a suspect component.
* Distributor Cap and Rotor: Inspect for cracks, carbon tracking, or corrosion. Replace if necessary – they're relatively inexpensive.
* Distributor Pick-up Coil: This sensor within the distributor sends a signal to the ICM. If it's faulty, there will be no spark. Testing usually requires a multimeter or a dedicated distributor tester.
* Crank Position Sensor (CKP): This sensor tells the computer the engine's rotational speed. A faulty CKP will prevent the computer from sending the signal needed to fire the coil.
* Wiring: Check all wiring associated with the ignition system for breaks, shorts, or corrosion. Pay close attention to the connections at the coil, distributor, and sensors. A wiring diagram is essential here.
* Computer (PCM/ECM): The PCM (Powertrain Control Module) or ECM (Engine Control Module) – these control various aspects of the engine, including spark timing and fuel delivery. A faulty PCM is a more involved problem, often needing professional diagnostics.
3. Testing Procedure:
1. Start with the easy and cheap stuff: Check fuses and relays.
2. Listen for the fuel pump.
3. Visually inspect: Look for obvious damage to wires, connectors, and components.
4. Use a multimeter: Check voltages and resistances at key points in the fuel and ignition systems. Use a wiring diagram to guide you.
5. Check for codes: If your truck has an OBDI or OBDII port, retrieve diagnostic trouble codes using a code reader. This can provide clues to the problem.
Important Considerations:
* Repair Manual: Get a repair manual specific to your 1994 Chevy K1500. It will contain wiring diagrams, specifications, and troubleshooting procedures.
* Safety: Disconnect the negative battery terminal before working on any electrical components.
* Professional Help: If you're not comfortable working on your vehicle's electrical system, take it to a qualified mechanic. Incorrect diagnosis and repairs can lead to further damage.
Since you have *both* no spark and no fuel, the problem is likely in a central component that affects both systems (e.g., the PCM/ECM, a major wiring harness fault, or a critical ground issue). Start with the basics, systematically eliminate possibilities, and be thorough. A repair manual will be invaluable in this process.
