Hey guys, I have a 2007 F-150 with the 5.4L Triton 3V. For months this engine has been shaking for around 20-30 seconds only on cold startups after it’s been sitting all night. 199,000 miles on it. One shop said it was a cylinder 4 misfire and replaced the coil and spark plug for just that cylinder. Ford dealer replaced all the spark plugs after having it for the entire week and it’s not fixed. Would a leaky fuel injector possibly be the culprit? I asked Ford Tech Makuloco about the VCT solenoid being the issue but he said it wouldn’t cause this. No check engine light is present.
Ford dealer replaced all the spark plugs after having it for the entire week and it’s not fixed.
Never go to the Ford dealer inless you're having recall or warranty work done. They're in the business of selling cars, not maintaining the one you have. Find an independent mechanic. Ask around.
Would a leaky fuel injector possibly be the culprit?
What popped up on live data when this happens?
LTFT stands for Long Term Fuel Trim. It works based on a percentage of perfect, positive or negative. If you're subtracting a percentage of fuel, that means one or more fuel injectors are putting too much gas into the combustion chambers. If it's a positive percentage, you're adding fuel.
For months this engine has been shaking for around 20-30 seconds only on cold startups after it’s been sitting all night. 199,000 miles on it.
You might be experiencing piston slap when the engine is first started in the morning. How often do you check/change the oil? The 20-30 second duration of idling rough then going away may be a symptom of piston slap. It will trip that same misfire code.
