Good afternoon yall,

I just recently bought a new ranger, 3L v6, 4x4, 2001 edge, manual. Pretty good little truck, I got it off a government auction. Here's the thing, the last inspection was 1/21, the truck was dirty and moldy when I picked it up, it's using 4 year old gas.
Anyway, let me tell you about the issue

As I'm driving it home, I notice that its misfiring just the shaking, I use my scanner, and it's cylinder 5, I pulled all the plugs, gapped, cleaned, and lubed and reinstalled. Cylinder 5 stopped misfiring, but then cylinder 1 started misfiring, it won't stop
I have new plugs coming soon, but I have changed out the ignition coil, and the spark plug wires. still there, its not as bad, but still worse. I'm also getting the code "P0171" Which is "System too lean Bank 1" which is cylinders 1/2/3

Blah Blah Blah cylinder 1, different plugs, different wires, different coil, I even swapped injectors and put injector cleaner in the tank.

Any Ideas? I know the 3.0 likes to burn its valves, so I HOPE it's not that.. thank you!

 

I think I would get rid of the gas, replace with some new high octane, gas. Change the filter and see what happens, possibly the injectors

 

🔧 Step-by-step diagnosis

1. Start with basics (most common causes)

Misfires are usually caused by spark, fuel, or air issues.

✅ Check the spark plug

• Remove cylinder 1 spark plug
• Look for:
  • Worn electrode
  • Oil fouling (wet/oily = possible valve cover leak or engine wear)
  • Carbon buildup (black/sooty = rich mixture)
• Replace if questionable (cheap and often the fix)

✅ Inspect the spark plug wire

• Check for cracks, burns, or corrosion
• At night, you can sometimes see arcing
• Measure resistance if you have a multimeter

👉 On the 3.0L, bad plug wires are very common

2. Test the ignition coil pack

The 3.0L uses a coil pack (not individual coils).

• Swap the plug wire from cylinder 1 with another cylinder
• If the misfire moves → bad wire
• If not:
  • Test coil pack output
  • Look for cracks in the coil housing

👉 Coil packs on these engines fail fairly often

3. Check fuel delivery

✅ Fuel injector test

• Use a screwdriver or stethoscope:
  • You should hear a clicking sound from injector #1
• If no click:
  • Check wiring
  • Injector may be dead

✅ Swap injectors (if possible)

• Move injector 1 to another cylinder
• If misfire follows → bad injector

4. Look for vacuum leaks (VERY common on 3.0)

• Inspect hoses near cylinder 1
• Spray brake cleaner or carb cleaner around intake while engine runs:
  • RPM change = vacuum leak

👉 The intake manifold gaskets are a known weak point

5. Check compression (important if above doesn’t fix it)

• Use a compression tester
• Cylinder 1 should be close to others (within ~10–15%)

Low compression could mean:

• Burnt valve
• Worn piston rings
• Head gasket issue

6. Check for oil or coolant issues

• Oil on plug → valve cover gasket leak
• Coolant loss or white smoke → possible head gasket

🧠 Quick diagnosis shortcut

If you want the fastest way to narrow it down:

1. Replace spark plug
2. Swap plug wire
3. Swap injector
4. Check compression

This isolates the problem without guessing

 

I got new plugs coming tomorrow, and fuel filter. I'll drain the fuel and get some ethanol free stuff maybe?

 

ok sounds good, i'd drive it around a bit when you can. can you feel the misfire? does it smooth out like at 2500rpm?