This may be a series of stupid questions but I'm a young guy trying to learn. I was having a misfire in third and fourth gear and I could hear a misfire at idle. So, I replaced all of my spark plugs.

I bought some platinum autolites from Advanced Auto and I asked if they were pre-gapped the guy said yes so I just went ahead and replaced them, didn't replace the wires. I made them hand tight plus another quarter turn and used compressed air to clean all of the boots. I started her up and it was running really rough so I checked everything, checked all of the spark wires were in the correct order on the distributor cap and everything seemed okay.

Is it my own dumb fault for not checking the gaps on the plugs? Should I get new spark wires as well?

 

try gapping them and then see, also new wires may help.

 

Wrong plugs - the 4.9 doesn't like platinums. Get some Motorcraft or Autolite coppers, gap them, and use some dielectric grease in the plug boots.

http://www.rockauto.com/catalog/moreinfo.php?pk=1017139

Motorcraft SP-435, $1.42 each at rockauto.com.

 

Really? Why wouldn't it like platinums?

 

Some engines are like that. My old BMW hated them.

 

"Just one of them things..."

And the guy was a moron for saying they are pregapped. Even if so, shipping will bounce them around and close 'em up.

Adrianspeeder

 

Yeah, you guys were right. I switched to copper and it ran like a champion, thanks! I have a random question though, I have a slow leak in my front right tire, can I use a can of fix a flat on it?

 

Spray all around both sides and the stem with windex to find the leak.

Adrianspeeder

 

I have a 93 f150 300 inline 6 cylinder that I inheritedfrom my Dad 2 years ago. Truck runs fine for about 5 minutes or so and it starts running rough and will cut off if I dont keep my foot on the gas. I've changed plugs,wires,new distributer cap & rotor button, fuel filter, & fuel pump and still no change. I really need to get this truck running . I would really appreciate some ideas about what it could be. Thanks