I have a 2001 F-150 4x4 AT. When I went to work this morning I noticed a vibration upon acceleration between 1500-2000 RPM. I'm not sure if it a vibration or a misfire. I need to drive it more but it only does it during acceleration and is fine at higher speeds. Anybody seen anything like this? Thanks in advance.

milkman00

 

a coil on plug could be going south on you.will miss very bad when being luged.in 4th and at 1500 rpms is where i get them to act up the most

 

Thanks for the advice. I just got a service engine soon light to come on in my dash today. A buddy of mine has a code reader so I'll see what the code is. I'll keep you up to date. Thanks

 

The code was 0303. I've looked it up and it just says cylinder 3 misfiring. Any ideas on what to look for? I know there are codes for the injector but could the injector throw the 0303 code? Thanks

 

usually we put in the new coil on plug assy and a new motorcraft spark plug.just to be safe.

 

We have a 2006 F150 5.4L that has given my husband fits for months. The problems it started having were: missing (or feeling like the transmission was jumping in & out of gear), vibration, would not accelerate when cold, drinking gas, etc. He has an OBDII code reader and would get misfire codes and other codes (I should have kept up with them). He did replace the coil packs, plugs, some kind of solenoid (I don't remember what it was called), and a dozen other things. I finally took it to the local Ford dealership and had them put in on their analyzer. They finally decided that the catalytic converter on the drivers side was stopped up. They took the O2 sensor off and it ran fine (although loud). These trucks had a TSB because of a vacuum line on the brake booster. My husband had already fixed that but the Ford technician said that during the time of the vacuum line problem it could have been running rich & stopped up the catalytic converter (my daughter's boyfriend was driving it at the time). Anyway, today my husband took care of the problem (if you know what I mean without going into details) and it is running great. He "worked on" both converters just in case. I know there are a lot of problems with the 5.4L that can't seem to be resolved. Hopefully, some of you might find that this is what your problem is and be able to "fix" it.