I have a 04 Screw 5.4 and the problem I am having is when you try and run the RPM's up around 1500 the engine starts to act like it is missing then the RPM's go down a couple of 100 then come back up. I have just ordered new plugs and going to replace them any other idea's

Thanks

Scott

 

Make sure you follow the TSB on the plug change and have plenty of beer handy????

 

Check engine light come on? What kind of mileage is on the truck?

 

No check engine light, 90,000 just hit today. I have listened to all injectors and all sound about the same.

 

Plugs changed and 400 hundred later broke off 4 plugs. Fuel filter changed and the dealer says that there is nothing wrong but the truck now idles so low that it acts like it is going to die when in gear. and the drop off of RPM's is still there. I think the dealership is just a bunch of idiots. Any other suggensiton on what it mght be. I was thinking the idle air control but don't know.

Scott