Alright, here i go again. just when my truck is running great something else happens.
I have a 1997 v8 4.6 4x4. 74000 miles. Coming home from work last week I felt a sudden loss of power. I was driving around 80mph , So I slowed down to 65 mph. My truck started to get pretty rough driving and my exhaust started to sound like a lawn mower. The check engine light flast 7-8 times and stayed on. My first thought was i blew a spark plug, so when i got home i replaced them all. STill the problem persit. I check my plug wires to see if they had spark and they all did. Then i thought maybe bad gas so i filled up when 91 octane and put a bottle of fuel injector cleaner in. Still no help. Rough idiol and poor aceleration, very sputtering. Does anyone have any ideas. So far i have replaced plugs, air filter, and gas filter and somewhat cleaned my trottle body.

 

Wires might still be suspect. They can break down and allow spark to reach ground through the wires instead of suppling all of the power to the plugs. Are they recent or are they the originals.

 

They are the original spark plug wires.

 

I am going through the same thing right now. I replaced the coils....1 at a time....and it got better. I say better because it is still not right. Yesterday, I took a timing light and checked every wire as it leaves the coil pack. 3 and 2 (same location in opposite packs) have a very different spark pattern. 3 "misses" every now and then, and 2 appears to miss every other one.

Anyway, I would suggest doing what I have done to verify whether or not the packs are working PROPERLY. Autozone and the likes (fools I tell ya) will test them, but not to an extent that is useful. They will say "Yes is has spark" or "No, it does not have spark."

 

Check it out. Today I went down to napa and bought a new set of spark plug wires. I put them on and to my supprise it solved the problem. I cant believe i tested all the wires and they seemed to be working fine. I went out on a ledge and bought new wires and it works. Thanks for the info guys.