Q: Misfiring after replacing plugs and coils in 05 F150

asked by on

After replacing the plugs and coils for maintenance, the truck misfires and doesn't idle correctly. We replaced all 8 plugs with motocrafts and all 8 powerpack coils. Truck ran perfect before the replacement but now won't idle and shakes horribly. Help me please.

My car has 125000 miles.
My car has an automatic transmission.

I would recommend starting with re-checking all of the plug wires to be sure they are properly connected. Misfiring and shaking may indicate that one or ore of them may not be firing due to an improper connection. If this does not solve the problem, you may also want to pull the spark plugs out to be sure they are properly gapped. In incorrect spark plug gap may also cause a misfire due to an irregular flash as it fires.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Misfiring after replacing plugs and coils in 05 F150

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Cannot find fuel pressure regulator under the hood of my 2001 f150xl V6 4.2

The fuel pressure regulator is beneath the upper intake manifold. That manifold has to be removed to gain access. Once you remove the manifold, you will see the regulator connected to the fuel rail and one end of the regulator...

Q: What is Bounce-Back associated with the power windows?

Your car’s power windows are certainly handy, but they can pose dangers to anything that might be sticking out the window while it’s being rolled up, including cargo and even hands (little kids love to keep their hands out the...

Q: Heater problems - 2005 GMC C5500

Hello. The fan speed control module (different from the resistor pack) is the common source for this behavior. The Part # is 89018778. If you need to have this done, a certified technician from YourMechanic can come to your location...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...