Hi guys. I recently picked up a 1998 2wd 4.6 F150. It has 290k miles but seems to be in good shape. Idle is a little rough and shudder under accelerstion a bit so I think its time to check the tune up and maybe some of the fuel system. This is my first Ford truck and I don't really know anything about these. When replacing plugs and wires, what the most successful brand? What else should I be looking at? I got it from one of my customers who used it on his pool service route. He kept a pretty decent record of stuff but that doesn't mean much. He told me he just replaced the front pads bit it's got major brake pulse so I know it needs rotors. So I'm willing to bet any thing he did might not always be the correct way. I need to make this truck last me a while so just trying to stay on top of things.

 

Replace the plugs with Motorcraft only. Check for engine trouble codes. Change the fuel filter. Check the fuel pressure at the shrader valve on the fuel rail. If it needs cops, Motorcraft are the most dependable. With that many miles on it, it would be a good idea to check the compression when you change the plugs to see if the engine is in decent shape mechanically.

 

Thanks. No check engine light on or anything but I'll check anyway. I think I have a fuel psi gauge still. Compression test and leak down would be good to do.

 

That engine has coil packs and wires, not cops.

It would not hurt to change the plug wires, also use Motorcraft. However, do the compression test first, if it's bad you may want to look for another engine.

On the spark plugs, do not use antiseize, and torque them to 28 ft/lb.

Throw a couple bottles of Techron in the fuel to clean the injectors.

 

What I feel feels like ignition or fuel related. Oil psi is good, burns a little oil but not smoking. Might need a cat soon too. It needs a by ch of little stuff so I'll tackle them one at a time. Need to replace the starter asap then get back on the rough idle issue.

 

Do the compression test before you get into the engine at ALL. If you have one or more weak cylinders, no amount of tuning it up is going to fix it. Buy the Motorcraft spark plugs, pull the old plugs and do the compression test. If it's good, put the new plugs in. If not, start thinking about a rebuild or replacement. The appearance of the old plugs can also tell you a lot.

 

Guys I appreciate the input but I'm sure that my rough idle is not because of mechanical failure. I've been working on cars for almost 30 years, 7 of those years was as a Harley Davidson dealer tech. What aim feeling feel a like ignition, fuel, or both. I'm new to Ford's so I'm just trying to get a feel of the common issues. A engine replacement is in the planning stages but won't happen until next summer. The weekends are my only time to work on the truck so whatever I discover will turn up then. I need to do front brakes, maybe a booster, and tires before getting too crazy. It's not undriveable, just has a rough idle.