cylinder misfire???

[zalewski84]

i just brought a 99 expedition 4.6 v8 last night check engine light was on auto zone said cylinder 8 misfire replaced coil pack and wires didnt work noticed tapping so i replaced fuel injector on #8 and cleaned carb now tappping is gone on one side but it is now on the other all my cylinders are misfiring on other side now can someone please help me thanks i dont want to replace all injectors if that is not the problem

 

[zalewski84]

Also before the problem started on that side i did have injectors out to clean them posible it needs new o rings? It is not leaking fuel

 

[toms89]

Misfires can be caused by mechanical issues, fuel or ignition. Mechanical issues generally do not come and go. Its either there or its not. Fuel or ignition can be intermittent and have many possible causes. If it occurred after you worked on it I would re-check all your work. Make sure all connectors are securely connected. No vacuum leaks etc.....

New spark plugs? Gap? Properly torqued? No vacuum leaks at the manifold where the injectors seat? No possible vacuum leaks elsewhere you may created when working on it?

Is the tapping more of a ticking sound such as an exhaust leak?? Exhaust manifold leaks are common on the expys as the studs rust and break. If a spark plug is coming loose and ready to eject itself it may sound like an exhaust leak as well.

 

[1997SCEBFEX]

If a spark plug is coming loose and ready to eject itself it may sound like an exhaust leak as well.

& smelling fuel as its leaking by....if I had only known back then.
Let us know what you find.

 

[zalewski84]

Took it to shop have no compression in # 3 and it melted spark plug tip looked online can be from injectors clog cause to lean fuel. Have it at another shop first one didnt know what je was doing wanted to replace engine

 

[toms89]

Took it to shop have no compression in # 3 and it melted spark plug tip looked online can be from injectors clog cause to lean fuel. Have it at another shop first one didnt know what je was doing wanted to replace engine

If you are speaking of a standard compression test. Not relative or electronic analyzer.. Zero or low compression indicates mechanical damage. Depends on how low... Do you have the compression readings?? As you said a melted plug could be from a bad injector creating a lean condition. This causes cylinder to detonate which can among other things damage exhaust valve, melt ring lands, or blow head gasket.

Leak down test would tell you what component is leaking. Intake or exhaust valve, piston rings or damaged piston, or head gasket. In any case the motor may likely have to be pulled.