Q: Misfiring after replacing plugs and coils in 05 F150

asked by on August 07, 2017

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.

Spark Plugs Replacement $98.11 - $669.97 Get a Quote

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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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


Experienced Mechanic?

Earn up to $70/hr

What others are asking

[Brake](/topics-brake-ford/) pads was hitting the rotors last week. I replaced the rail clips and thought the problem was fixed, but It's touching the rotors again slowing the vehicle down. Any ideas?

Turn signals, heated seats, driver and passenger windows won’t work

Hi Brenton. Thanks for contacting us today. The components you've listed are controlled by multiple, independent fuses, so it's likely that either all of them are blown, or more likely that you have an exposed electrical wire that's creating a...

Where is transmission mount located in 2003 cavalier

The transmission mount is on the left side of the vehicle concealed behind the wheel/tire assembly and the inner fender lining both of which must be removed to gain access to the mount. The job requires a torque wrench as...

on my peugeot 208 the digital speedometer do not work to turn on

My best recommendation in this circumstance is to call your local Porsche dealership and maybe pay them a visit. The salesman at the dealership should be very familiar with the features of these vehicles and will likely be happy to...

Does the PCM in my 2000 Chrysler Cirrus have to be reprogrammed after replacement?

The repair information from Chrysler says an OEM level scan tool must be used to update the mileage and VIN number in the replacement PCM. If this is not done, a diagnostic trouble code (DTC) will be set. You'll want...

Car stalls. Vapor in fuel rail.

Hi there. What you are describing is commonly associated with an internal problem in the throttle body or a vacuum leak. However, it is also possible that you have a problem with air fuel ratio sensors or ECM is sending...

Engine cranks but won't start.

Hi there. There could have been a vapor lock in the fuel line, but also if fuel level is low, then the fuel pump will draw air when going up hill or starting and stopping fast. If the fuel pressure...

I have a 2005 Suzuki Forenza and I have a code that's saying it lost communication with engine, EMC, so was told I needed a new computer

The U0100 code is generic as it has the same frame of reference on all vehicles. Somewhere within the CAN bus network (Controller Area Network) an electrical connector, wiring harness, module has failed, or the computer has crashed. Assuming this...

Rattling sound coming from beneath steering wheel

The most common cause of this would be a clicking relay or something else that is loose. This is a more uncommon issue that will require diagnosis to confirm. A qualified technician, such as one from YourMechanic, will be able...

Related articles

A Buyer’s Guide to the 2012 Ford F-250
When When it comes to large, heavy-duty pickup trucks, the 2012 Ford F-250 only has two competitors – the Chevrolet Silverado HD and the Dodge Ram 2500/3500. Though the F-250 doesn’t outperform the Ram in the towing department, it certainly...
2012 Chevrolet Malibu vs. 2012 Ford Fusion: Which One Should I Buy?
When you want a midsize sedan, you’re looking for something that will offer you the best fuel economy for the size as well as additional safety features that will keep your family safe while you’re driving across town or around...
The Best Used Cars to Buy If You Just Had a Baby
Having Having a baby will completely change your life. Your activities and hobbies will change. Your sleeping patterns will change. Chances are good that you’ll also be looking for a change in vehicles. You need to ensure that your car...