Hey there, I started with a standard changing of the spark plugs. When complete I got engine code 0304: Missfire cylinder 4. The engine was shaking really bad. So I replaced the coil. It is not shaking as bad now, but there is still a missfire. I reset the engine codes. And now I got codes 0304, and 0132 shortage to O2 sensor. I have replaced the coil a second time to #4 and the engine is still missfiring. So I replaced each coil tube with the new coil one at a time to see if it was a second cylinder miss firing. With each change there was a missfire. Engine code still said #4. What can it be? I have thought that it could be 2 cylinders missfiring but that seems unlikely to me. What do you all think? What are my options without taking it in to a shop? Thank you for your help. You all have helped me before, hoping you can again here.

 

I think I understand Wat ya did but not sure. Im guessing you have a 4.7 but I'm not sure (can't see your signature in mobile) but if I were you I would take a coil off a cylinder that isnt misfiring and put it on the cylinder that is misfiring.

 

Gen 1 with coil packs, yea it's a damn 4.7.

Check wires to that particular coil pack. In the future, have one new pack and use it to see if the problem goes away when replaced, or follows the replaced coil pack as you move it elsewhere.

IndyDurango

 

It is a 4.7L V8. I did a voltmeter test and the coil pack I replaced was still good. So are the two new ones I bought. Still reads cylinder 4. Went through and unplugged a few, then replugged checking to see how the engine was running. Reset engine codes, then it came back on for the same cylinder. So I am thinking possible bad rings and or valve issues with that specific cylinder. I have suspected rings and valves already for all the cylinders as I have lost fuel efficiency and am burning to much oil. So that isnt totally new, but the fact that I lost compression like this over a routine spark plug changed is very puzzling. I have removed the spark plug, regapped and inserted again. Still miss firing.

 

Do a compression test on all cylinders and report your findings. It could be a number of things. Low compression due to mechanical failure. power to the coil, Test this with a spark tester, http://www.amazon.com/Lisle-20610-In.../dp/B0002STSC6 , pull the coil off, plug it into this tester and the spark plug and fire up the engine, finally swap fuel injectors around and see if the misfire follows the injector.

 

lmfao......:d

 

Yo HS, in Vegas for the week. Get away and come south for a brew.

IndyD

 

Actually I would do that in a heart beat but I just got back from Phili which I spent 5 days in a conference. My **** is in need of rest....LOL.....As well as my pocket book!

 

Did you do a compression test like the member mean green had recommended? Because i would add a running compression too. Have you swap injector yet from another cylinder? and replace the spark plug. If you have done all of these, Then its time to pull the cylinder head. You may have a burnt valve or bad valve seat.