Long story short: My engine was running very rough a ways back so I replaced the plugs (Motorcraft), COP's, and injectors. Ran much better after this. A few months later it rained and somehow water got up in the engine. (Don't remember driving through any large puddles or anything). It ran very rough again after this. I probably let it run like this for a couple months.

Last weekend I replaced 6 of the COP's with new. (Damn E-Bay seller sold me only 6. Guess I should have read the very fine print). Anyway the engine now runs slightly better but is still running pretty rough. I'm thinking that either the other two COP's may be bad or maybe the plugs got fouled by the engine running rough for a couple months.

Any ideas on why the engine still runs rough? Could it be two bad COP's or fouled plugs, or maybe even something else. Also, it does throw an engine code. Haven't identified which one yet. I also reset the computer and it threw the code shortly after.

Thanks for the help.

1999 F150 5.4 V8, 4x4 210k

 

Option #1, get the code identified
Option #2, get the code identified
Option #3, get the code identified
Option #4, remove the plugs and check if they are fouled or water is present in the plug wells. Also try changing out two of your new COP'S with the two that are old. Look for other things that could cause a rough idle such as a broken vac line/connection etc.

 

You did use this stuff, right?

==> http://www.fcsdchemicalsandlubricant...tegory=Greases

And, X2 on the codes....

< placeholder fer future Jbrew BatSignal>

MGD

 

Thanks for the replies. Yes I used the dielectric grease. Just seems like the engine starts running rough even with minimal moisture. I'm pretty sure that it's due to the moisture, since it was running good before and started running rough right after the rain.