Ok, so I was driving around today and thought something was off. Just seemed like there wasn't as much power as before but still got up to speed. I was taking a small pass up hill and had the pedal floored and topped out at 54mph. It down shifted and the rpm's went up to 5000 but no acceleration and then the truck started shuttering. I checked all fluids and everything is good. I have a 4.6 with 126k, its a '98. I am at a loss right now. The only thing I can think of is that its not firing on all cylinders, I hooked up a code device and didn't come up with any. I think I need to replace plugs, wires and I know I need to replace belt. Any help would be appreciated.

 

Sounds like it could be a symptom of a cylinder misfire. If you are due for a tune up, I'd start there (plugs and wires). A restricted fuel filter can also cause lack of power. I'd do all the maintenance stuff first-go from there.

 

That's what I was thinking. I already replaced fuel filter. How do I go about checking the cylinders? I'm new to this. I know its a hell of a lot cheaper to do it myself. And I can get the parts cheap. I have read the forum on plug changes but have never done it. Any help would be appreciated.

 

You can run the engine and disconnect plug wires one at a time. As you disconnect each wire you should hear the RPM's change and engine stumble a bit. If any cylinders don't seem to be affected by this, you've probably isolated your miss. Now you can determine if it's a plug, a wire, an injector or other problem by switching components with that of a another cylinder and then see if the miss changes to the other cylinder.
If the engine is near tune up interval, I'd just go ahead and replace plugs and wires.

 

Im thinking I just need to replace plugs and wires. I have no idea if the previous owner did and I think it is probably time. When are you suppose to? And I am new to this, is it pretty much plug and play or will I need to get it tuned after I install everything? Thanks guys!