hesitates on acceleration (full pedal). double tapping pedal, accelerates normally. 5.4l 3v
Check engine light on? Miles on the truck?
Can you explain when this happens more fully?
117,000 miles. changed fuel filter, flushed manifold, changed plugs, checked cops, fuel pressure test. no codes, no CEL. runs like a champ until it warms up. warmer it gets, the more i have to nurse the gas pedal. full pedal results in vehicle hesitating on acceleration until it passes 4,000 rpm and then the tranny shifts to passing gear and the truck takes off. full petal, then let off and tap will allow passing gear to kick in. shifting manually (auto trans) avoids hesitation. have had it for 3yrs with zero problems. put roughly 8,000 miles on it since purchase. also checked MAF. no noise from cam phaser/timing chain. i’m in limbo.
That’s a tough one! It sounds like a lean fuel condition on closed loop operation. When you give it the boot and the trans downshifts, it goes into open loop and richens the mixture and off you go.
Maybe an air leak in the manifold - crack or failed gasket. Or an air leak downstream of the MAF sensor before the throttle body.
I’d also suspect the coolant temp sensor just because of age. It is cheap, maybe replace that pro-actively.
Your F150 has a drive-by-wire throttle system.
Instead of having a throttle cable between the accelerator pedal and the throttle body, your truck had an accelerator pedal position sensor,
which sends a signal the computer, and from that signal the computer operates the electronic throttle body.
That’s the area I’d be looking at.