Hii have a 98 Ford F-150 with the 4.6L in it and on acceleration the truck runs like crap. When it idles it runs fine. The Check engine light has been flashing but will periodically go solid. Im also getting really crappy gas milage. I am trying to think of what could be wrong with it since AutoZone will be closed due to the holidays. I recently got the truck stuck in some snow and the engine compartment was covered in snow, Most of the snow is gone now but the problem still remains that it is running like crap. If you can think of any reason that it would do this that would be great. The engine feels like it is misfiring on one of the cylinders but i can figure out which one that is really easily. Any help is greatly appreciated. Thanks

 

sounds like u got spark plug wires wet and maybe ignition also dry every thing out and spray with spray silicone might help

 

I will second Davids idea, any kind of moisture gets into the spark plug wire boot will cause misfiring. Remove the boot from the plug and blow out the holes and dry the boots. Many times this problem will cause the boots to arc, and you will have to replace the wires eventually.

Thanks for mentioning the snow on the engine, that sure makes offering advice easier.

 

if the problem started before the snow i dont think thats the answer have the codes pulled may be a missfire or could be clogged egr ports this is common for this motor also could have vaccum leak get codes first

 

Well i solved the problem for a while. Blew out the spark plugs and actually changed them because it turns out that the person that had the truck before me hadnt changed the plugs. But now everytime i go through water even slowly i have a misfire in cylinder 8. Is there anyway that i could stop this from happening. I blow the plug out and it fixes the problem but then i go through even the smallest puddle of water and it starts again. Im thinking this isnt something that should be happening. Any ideas?