I just purchased a 97 f150 4.6 and it does have a miss fire but the last couple of day i have noticed that form off idle to about 2000 rpm lack of power and throttle response plus a backfire in the engine. Give me an idle. Thanks

 

you need to do a full tune up. Wires plugs clean the throttle body fuel filter new 02's and all. Trucks going on 14 years old. Your gonna have to work on it if you want it to run good.

 

I was thinking the same thanks

 

i had a 97 F150 with the 4.6 a while back and it did the same thing...plugs and wires fixed it right up...

 

You guys are great thanks

 

You may want to check out cyl #4 in particular. The heater tube that sticks up from the intake manifold at the rightside rear (passenger side) of the intake and connects with one of the heater hoses has a tendency to leak coolant that drips down right into the #4 sparkplug hole. This causes a miss in that cyl. Check the hose clamp and even install a second clamp if possible. Take care.

 

Thanks for the info