97 F-350 tune up questions
 

Hi everyone! I have a 97 Ford F-350 with 89,000 miles. Although it runs fine, I have never done a tune up on it. I have noticed when I use it for towing, that it lacks a little power that it once had. I would like to do a tune up now, and have bought all the necessary components. I have plugs, plug wires, rotor, cap, PCV valve, fuel filter, air filter, and serpentine belt.

My questions: Where is the PCV valve located? I did a quick glance on the valve covers, but didn't see anything that stood out.

Also, how do I release the fuel pressure safely when changing the fuel filter? I remember changing the filter on my F-250 years ago, and I had to release the fuel pressure first. Problem is, I don't recall the steps.

Also I was told by a friend of mine to pull the hoses off the throttle body, open the butterfly valves and clean out the throttle body. Carb clean and a bottle brush. Disconnect the battery and let it sit for ten minutes. I'm not sure exactly what is in there to clean. Anyone have a pic of this?

Any other suggestions??

Thanks alot!!