So you’re ready to run errands, but when you put in your keys to start the Ford F150 truck, the engine cracks but won’t start. Frustration arises, and you’re left wondering what the problem might be. Does that sound right? Well, you’re about to understand why and how to fix it.
Why is my Ford F150 turning over but not starting? Your Ford F150 is turning over but not starting, likely due to a failure in one of the key systems needed for combustion: the fuel, ignition, or timing systems. Without the proper spark, fuel, air mix, or timing sequence, the engine tries spinning over via the starter motor but fails to fire and run under its own power.
Check for issues causing these problems, and you will have the right solution to the starting problem. Check out the in-depth discussion of these three major issues.
Why Is My Ford F150 Turning Over But Not Starting?
Ford F150 truck deserves some respect when it comes to staying out of trouble. However, there are times when you will experience serious issues with it. One of those is when it turns but doesn’t start. You’re left red-faced, asking yourself, ‘Why is my Ford F150 turning over but not starting?’ Luckily, we have come up with common reasons for these problems and how to fix them. Let’s jump right in!
A Dead Or Weak Battery
The battery may not be able to provide enough electrical current to both the starter motor and ignition system simultaneously. When you turn the key to start the engine, the system draws a large amount of current through the battery to power the starter solenoid, starter motor, and ignition components.
If the battery is low on charge or at the end of its life, it will be unable to meet this high current demand. That will cause the engine to crank/turn over as the starter motor engages but does not actually start since insufficient power is getting to the ignition system to spark and combust the fuel.
Solution:
- Visually inspect the battery terminals and connections for corrosion, looseness, or damage. Clean terminals as needed.
- Use a multimeter to check the battery voltage – it should be 12.6V or higher when not running. Below 12V indicates it needs to be charged or may be bad.
- Try jump-starting the vehicle with cables from another battery to see if it starts. If it does, the battery is likely bad.
- Have the battery and charging system tested at an auto parts store. They can check voltage under load to confirm battery health.
- Replace the battery if it tests bad. It’s a quick fix, but if you feel uncomfortable, take it to an auto shop where you intend to buy the battery, like AutoZone USA. They might replace it for you for free.
- In very cold weather, a battery may temporarily struggle to provide enough current, regardless of age.
- Test the alternator to ensure it is charging the battery properly when running. If there are signs it might be faulty, you must replace it before the next crank.
RELATED: 2013 Ford F150 Starting System Fault
Failing or Faulty Ignition System
A faulty or failing ignition system can cause the Ford F-150 to turn over but not start due to an interruption in the spark needed for combustion. The ignition system is responsible for generating and properly timing the spark. This ignites the air-fuel mixture in the engine’s cylinders, which is essential for combustion and startup.
If components like the ignition coil, distributor cap, spark plugs, or ignition wires become damaged or fail over time, they may not produce a strong enough or properly timed spark. Without a consistent spark energy delivered to each cylinder at the right point in the engine’s cycle, the air-fuel mixture will not ignite fully. The chemical reaction that provides energy to move the pistons cannot occur successfully.
As a result, the engine cannot generate power from the combustion process and will simply turn over without starting up properly due to the lack of spark from a faulty ignition system.
Solution:
- Inspect spark plug wires for cracking, splitting, or loose connections at both ends. Tighten loose connections or replace them as needed.
- Remove and inspect spark plugs. Look for worn, fouled, cracked, or improperly gapped plugs. Replace plugs if issues are found.
- Check the ignition coil pack/coils for signs of cracking or damage. Test with a multimeter or coil test kit.
- Test the ignition control module/crank position sensor with a scan tool or ohm meter. Replace if not within specs.
- Examine distributor cap and rotor (if applicable) for cracking oil/damage. Ensure wires are properly routed.
- Inspect high-tension wiring running to each spark plug from the distributor/coil pack.
- Check spark plug wires/boots for oil/fuel contamination, which can conduct electricity poorly.
- Test individual spark plug fires using a spark tester or jumper wire while cranking.
- Check for diagnostic trouble codes pointing to an ignition system fault.
- Consider swapping a known good coil pack/ignition module from another vehicle for testing.
Bad Crankshaft Position Sensor
The crankshaft position sensor plays a crucial role in allowing the Ford F-150’s engine to start by providing positional data to the powertrain control module. It monitors the crankshaft’s rotation and sends an electrical signal to the PCM indicating the precise angular location of the crankshaft at all times.
The PCM relies on this real-time positioning information from the sensor to properly determine piston location and fuel/spark timing. If the crankshaft position sensor fails or becomes faulty, it will not allow the PCM to track crankshaft rotation accurately. The PCM cannot appropriately coordinate fuel delivery and ignition timing to start the engine without knowing where the pistons are in their cycles.
So when the bad crankshaft position sensor is unable to provide a correct signal to the PCM, the engine will simply churn over but fail to ignite and start-up because the PCM does not have the sensor data needed to time ignition and fuel injection correctly for combustion to occur.
Solution:
- Locate the crankshaft position sensor, usually near the crank pulley or timing cover.
- Inspect the sensor or wiring harness connections for any obvious damage, corrosion, or oil/debris contamination. Clean or replace as needed.
- Use a scan tool to check for trouble codes pointing to a crankshaft position sensor circuit issue.
- Perform a voltage drop test on the sensor wiring while the engine runs. An out-of-spec resistance could indicate a faulty sensor.
- Compare the sensor voltage signal pattern with specs using an oscilloscope or multimeter. An irregular or no signal may mean replacement is due.
- Attempt to start the engine with the sensor disconnected – it should not start, verifying it’s an essential component.
- Try back-probing the sensor connector with the engine running to check for a valid signal pulsing to the PCM.
- Test resistance between sensor terminals and compare to factory specs. Outside specs would require replacement.
- Swap in a new known good sensor from a junkyard/donor vehicle to test if symptoms resolve.
Fuel System Problem
If the fuel system is experiencing problems, it can cause the Ford F-150’s engine to turn over but fail to start. The fuel system is responsible for properly delivering gasoline under pressure to the engine’s cylinders so it can mix with air and be ignited by the spark plugs.
Issues like a clogged or faulty fuel filter or injectors preventing sufficient fuel flow, a weak or defective fuel pump unable to pressurize the gasoline adequately, or problems with the fuel pressure regulator that can’t maintain the correct fuel pressure directly impact the engine’s ability to run. Without the precise air mixture and proper volume of pressurized fuel being injected into each cylinder space, successful combustion cannot occur when the spark plugs fire.
As a result, while the starter motor can spin the engine over, the air-fuel mixture in the cylinders will not ignite or burn efficiently due to fuel system shortcomings. Despite the cranking efforts, this prevents the engine from starting and generating power from combustion.
Solution:
- Check the fuel pump relay/fuse and replace it if blown or compromised. The pump should run when the key is in the ON position.
- Inspect the fuel filter for debris or contamination and replace it if it is dirty. A clogged filter limits fuel flow.
- Test fuel pressure with a gauge. Pressure should hold steady above spec (usually 35-58 psi).
- Check for the fuel pump priming sound in the tank for 2 seconds when the key is turned. Absence means the pump is faulty.
- Inspect, clean, or replace the fuel injectors if gummed up or dirty.
- Inspect the fuel pressure regulator and replace it if pressure is out of factory specification.
- Check fuel lines for cracks, kinks, or leaks that would cut off fuel supply.
- Check that the fuel shut-off switch or fuel cut-off relay is functioning properly.
- Attempt to start with starter fluid sprayed into the throttle body if it’s a carbureted engine.
- Scan for codes pointing to fuel delivery problem areas like low pressure.
Keep Your F-150 Running Smoothly
With so many systems and components working together seamlessly in your Ford F-150, it doesn’t take much for one small issue to cause startup problems. If your truck is turning over but failing to fire up, don’t despair – the cause is likely an easy fix once properly diagnosed. Taking some time to carefully inspect high-failure areas like the battery, ignition wiring, fuel pump, and sensors is key. But if you’re still unsure where the problem lies, consider seeking a professional diagnosis from a trusted mechanic. An expert set of eyes and diagnostic equipment can quickly uncover underlying issues. Their repairs will have your F-150 up and running in no time. Keeping up with routine maintenance, like filter changes, will also help prevent larger future problems. With a little diligence, you’ll be back to smoothly starting and enjoying many more miles in your F-150.
