misfire/hesiation

[97ranger4x4]

After I got back from my 1700 mile road trip I noticed a hesitation at idle. Well just driving to the store a few min ago it has turned into a misfire. I do not have a CEL and it is not super bad. I guess I will pull the spark plugs when I get home tonight and see if I can find one that doesnt look so hot. But all my plugs/wires were replaced in the last year or so. I have motorcraft plugs in there now.

I figured doing all that hwy driving would be good for my truck... I guess the good thing is it didnt skip a beat while driving all that distance.

Let me know if anyone has anything else the reccomend checking. I have been meaning to clean out my air filter as well. But it doesnt look too bad...

 

[jasonl]

If it's a dead miss as in one particular cylinder isn't firing you could pull one of the coil wires at a time, start it and use some insulated pliers to hold the wire above the coil and see if it's arcing and if it changes the mis-fire you've got and pin point which cylinder it is that way. If the coil has died on one cylinder it will be obvious when you hold the wire above it and there's no spark or a real weak spark compared to the others. At the very least it will tell which cylinder is not firing. Do not get zapped though !!!!

 

[97ranger4x4]

CEL came on this morning. Pulled the code and it was a P0175 which is Bank 2 System Rich. I am guessing it is getting that because one of the cyl is misfireing causing an inefficient burn. Anyone know what bank is which? I thought bank 1 was driver side and bank 2 is passangers side. If thats true, I think it might be cyl 1 causing the misfire. A few months back it was misfireing and I threw and old spark plug (autolight) and it stopped so I never went and replaced it with a new motorcraft one.

 

[jasonl]

Bank 1, cylinders 1,2,3 from front to rear is the passanger side.
Bank 2, cylinders 4,5,6 from front to rear is the driver side.

How many miles do you have on it? If you replaced the plugs and wires in the last year and then had to already replace one of those plugs, I would start there.

 

[97ranger4x4]

Yeh it has 140k on it. I replace the plugs a year ago with motorcrafts. But 2 months ago I fouled plug 1, which is on the passangers side. So that means its on Bank 1

So I must have fouled a Drivers side spark Plug. I will pull them today after work when there is light out, check to see the condition of the 3 plugs, (ill check the other 3 just in case) and go from there.