Engine hesitation...

[Autumnstang97]

Hello folks...

Question here...

I have some engine hesitation with my '02 XLT 4.6.

The idle is fine and initial take off is ok, but when the vehicle get moving around 45-50 miles per hour, only sometimes it starts to vibrate and hesitate, then sometime goes to normal, but feels like there is power loss. It starts up and idles just perfect, even revving it up in Park, it's fine, just under load when the car is accelerating, and it's only sometimes.

I have since changed the spark plugs (Motorcraft) and one coil plug bc it came apart when I removed it, and I thought it was that. However it's still doing it. Could it be that another coil plug is bad somewhere? I have no check engine light, and have not run the handheld for any codes...

Any insight?
I would have to replace all the coils @$50 each (Motorcraft) and that won't fix it. However I may as well bc I love that car and I won't be getting rid of it.

She has 165k...

 

[docraymund]

Start by checking fuel pressure. You may have a failing fuel pump or a clogged fuel filter.

 

[rosario1991]

I also think that he needs to start from fuel pressure.

 

[AbbadonTD]

Check your THROTTLE CABLE for tightness

 

[AZ59apacheguy]

COP starting to fail after heating up? It won't throw a code untill several miss-fires occur. This happened to me a little while ago. Engine was fine at start up, but after driving a while got a real bad hesitation and a check engine light. Hooked up my code reader and computer said I had a miss-fire on the #4 cylinder. Changed out that COP and it went away. I later ended replacing ALL COP's since they looked like original Motorcraft ones, motor has run fine since then.