Odd Loss of Power/Acceleration

[bring_em_on]

I have an '05 5.4l. I was pulling my boat the other morning and as I was coming to a stop at a red light, the light turned green so I hit the gas to speed up. Only it didn't speed up! I looked at my instrument panel and saw the "wrench" lit which I assume means fix engine? No other lights lit and oil/temp are all normal.

Anyway, I pull over to the shoulder. The engine is still running, it just won't accelerate. I come to a complete stop and the engine is idling fine. It's not even a little bit rough at idle. I put it in park, hit the gas and nothing..just idling. I kill the engine, wait a second and start it right back up. Ran like a champ after that. That was a couple of days ago and it has been fine since.

I'm at a loss on the cause. Any ideas?

Thanks.

 

[ELVATO]

When you say it wouldn't accelerate, would it not rev, or did it rev, but the truck didn't move? If the latter, I'd think it was the transmission? Did you get the code pulled (you can do this at Pepboys, Advance, or Autozone).

 

[bring_em_on]

It wouldn't even rev but it idled very smoothly. Since it wasn't the check engine light that came on, I didn't get a code. I don't have my owners manual handy but it was the "service needed" or whatever that wrench light means.

 

[Derks88]

I had the same deal happen with my F-150. Ended up with a bad intake valve on cylinder 8. It would only do it intermittently when I hauled a trailer. Then it started without the trailer and all the time. I would get it looked at soon.