Another suspect might be the IAC (Idler Air Control) valve. On my old 2001 F150 replacing it cured all rough idle problems. Cheap and easy DIY fix too.

Ford F150: How to Clean/Replace IAC Valve | Ford-trucks

2000 Ford F150 Idle Air Control Valve - from $47.99+ | AutoZone.com

 

Thank you.

 

I would bet the plugs need changed if they haven't changed the air filter.

 

yeah, we thought that too. It looks like quite a complicated procedure to change them though. I looked at a video. Guess that's something else for a mechanic, not us!
I remember when you could tap a Chevy starter with a hammer to get it to start. Those were the days!

 

A 4.6L is among the easiest engines to changing spark plugs on. They're right on top, facing almost straight up. Unplug the coil connectors, take out each coil's 7mm bolt, lift out the coil & boot, then drop a small spark plug socket into the well & back it out. Apply a little silicone grease to the ring of the boot where it seals to the head, DO NOT OVER-TIGHTEN THE SPARK PLUGS (barely wrist-tight is enough - just 12 lb-ft), seat the boots, replace the bolts, and reconnect the wiring. Done.

 

Uh huh.... Easy peasy. I appreciate your instructions though. I'll remember the tip about not over-tightening the plugs.

 

IMO, 12 ft/lbs is way too close to the original Ford spec of 11 to chance stripping plug threads.

The newer recommendation was 27(?) ft/lbs. That gives me a better feeling, since the heads with extra threads didn’t get into many ‘03s. You have a 2000, which should have the skimpier three thread heads.

 

According to the '96 service manual, the early spec for 4.6L plugs (before PI heads in '02) was 7-15 lb-ft. That's why I suggested 12.Yeah, well on many recent & modern vehicles, changing the plugs involves removing the intake manifold, including its wiring, vacuum lines, and several other parts.