Hey everyone, I'm new to this forum, but I've stopped by before and read different topics. My 2002 f-150 lariat supercrew is having sputtering problems and I'm pretty sure its the spark plugs. Its starts just fine, but during some lower speeds its putters, then corrects itself. I was just wondering if the system that you get your yearly truck inspection would tell you if your spark plugs are bad. I just didnt want to pay 300 bucks before I knew it was time for new plugs. Any help would be appreciated, thanks!
also, I failed to mention, that the idling problem tends to only happen at lower speeds or when sitting in the driveway. Could this be the fuel filter causing this, and how would I know if my filter is bad?
First, welcome to the site. Formalities over, lets have some fun. Testing spark plugs? Unfortunately, others will have to give up the easy way. Thats if there is one. I mean who has a scope in their garage? Spark plugs in todays engines are designed to run 100K. Changed mine at 95K, engine now has 175K. Will probably change again this winter. Spark plugs, if left alone will last longer if left alone. Its us jerks messing with them that messes them up. We are not NASCAR running at 9000RPM. There is a whole aray of things that cause an engine miss. Follow Fords recommendation and their plugs, not a substitute, and be happy.
Sounds like you might have a COP (coil on plug) going bad.)
Easiest way to check is crank engine. While its giving the sputtering you speak of. Unplug 1 cop at a time see if the engine starts to miss and sputter worse. If so. That cylinder is fine. If you unplug one and nothing seems to change. Thats the cylinder you are having problems with. Replace the spark plug and the COP.
Thanks everyone for the advice. I went to Autozone yesterday and had my truck codes read, and it popped up with no codes. I'm not totally sure how those code machines work, but if one of my cops were bad, would it give me a code? I went ahead and bought a new fuel filter, figured it was time anyways, so I'll swap them out and hopefully it'll be better.
If you have a bad coil or coils it may not throw a code. I've chased this problem myself and it can be frustrating. I ended up with a coil that only wanted to act up when I did not have my tools with me, but ran fine when I did. I ended up going old school and diagnose the bad coil like ujslost described.
Yeah, I'm beginning to think I may have a bad coil. I will try to the "old school" test on them and see what I come up with. I did put the Seafoam stuff in there, and it seemed to help. Just curious, but if I do end up having a bad coil, how long can I drive on it before it completely dies? Is it something I can deal with for a few weeks, or something I need to fix immediately?
I suggest fixing asap. This may or may not happen to you. But with the injector shooting fuel in that cylinder and nothing burning it off. You will eventually wash your cylinder wall down, and then have gasoline in your oil.