So I went to pass someone today on the highway, I pushed down half throttle and made it downshift to I think 3rd gear (3400 rpm). I could have counted to 3 before it downshifted and the throttle was back on track. What causes this? For the record it's an 04 5.4 3V Lariat 4x4 w/ 160k. I also continued to test this and time after time, I pressed down the gas, and nothin for about 3 seconds. Finally, it caught on and locked into gear and after that, it felt like it was missing, it would lerch and then let up again and repeat.

If there's any thoughts whatsoever I appreciate it, Thanks!

 

I don't know if this will help but my mom's 1999 5.4L started to miss, and then it wouldn't even downshift on the highway. The truck got to the point where it would just shake. Guy at the dealer got in, put it into drive, and gave it some gas(with brake engaged). He told me that it had a bad miss,(really?) probably on cylinder #4. This motor was bad for leaking coolant onto the coil for cylinder #4. I don't know if this applies with the '04.It was a gradual process, starting with the SEL coming on. Don't know if this will help, but it is worth a shot.

 

When was the last time you changed plugs/wires/fuel filter/air filter/cleaned your MAF?

Is your check engine light on? Might be worth taking it to autozone and having them check for stored codes even if you don't have a CEL.

 

I bought the truck at 144k. I don't know when the last owner had all that stuff done. He was really good at keeping the maintenence up to date. Air filter is perfect (K&N). So, those are the things it could likely be? It wouldn't hurt to change plugs and wires anyways I guess.

Thanks

 

After your sure the maintenace is up to date you might consider a programer- xcal, edge, superchips or what ever. The fly by wire hesitation can be programed out along with other things that make the 3v kinda sluggish.

 

Clean the MAF. After you clean it, clean it again and replace that K&N with a dry type air filter.