My 04 EDGE 3.0 when sitting in Park will not rev up past 3500 RPM. The check engine light has been on for awhile showing P0316 and I believe P0302. My mechanic said number 2 is misfiring; the coil packs/wires/injectors are all good. He said eventually if I want to keep it a new engine would be needed, but as long as it's not burning oil it should be okay to drive for awhile. Can anyone give me any ideas as to why it won't rev up? I wouldn't think one cylinder misfiring would cause that. Thanks in advance.

 

Low fuel pressure would cause it, that could be from a weak pump or a clogged fuel filter.

 

Welcome to FTE.

Lets think about this some more.

If your sitting in park/no load on the engine & revving it that high, you've probably hit the Ford programmed in, computer controlled rev limiter, so the engine won't over speed, come unraveled & make a mess!!!!

If you have a misfire, would be a good idea to get it properly trouble shot & put right without throwing parts at it, so the cat converter isn't over heated & damaged from having to process all the misfire fuel being dumped into it.

How were the plugs, wires & coil pack determined to be ok?

Did the codes come about suddenly after some event, or slowly over time?

Have a read here for a list of suspects on the P0316 https://www.obd-codes.com/p0316

Seeing as how this is a 3.0L that has a history of cam sensor & cam sync assy problems & we don't have any maintenance, repair, or other diagnostic info, listen closely at idle to that area & if you hear a cricket like squeak from that location, put the cam sensor, or sync assy on the suspect list.

On the P0302 & P0316 codes, add the fuel injector & valve seat recession to the suspect list, so maybe consider doing a compression test on the misfire cylinder, when your sure which one it is.

Maybe consider using a mechanics stethoscope, or fashion one from a long wooden dowel, broom handle, length of hose, or tubing, or a long screw driver, one end on the suspect, the other to your ear & with the engine at idle, have a listen for unusual noises around the cam sensor/sync assy area, & the suspect fuel injector, for clicks going missing in time with the misfire.
EDIT: With your inductive timing light attached to the suspect misfire cylinder pug wire, also watch the timing light, while listening with the stethoscope, to see if spark is going missing in time with the noise.

More thoughts for consideration, let us know what you find.

 

It being an '04, you also have to consider the possibility of bad heads.

https://www.ford-trucks.com/forums/1...l#post15040592