Hi! I have a '96 Explorer with the 4.0 V6. I've had my spark plugs changed twice within the last year because the Number 4 sparkplug has lost its electrodes.
After I start the car each morning the car runs rough for 2 minutes, then smooths out. Today the "Check Engine" light came on... computer code P0304 - misfire on number 4 cylinder - ARGH!
Questions are:
1) What could be causing this? 2) Which cylinder is Number 4? I think it's the driver's side front - is this correct?Thanks, ...Jerry
Try replacing your wires. That worked for me, when I had a misfire code.
Paul
Jerry you say your #4 spark plug has lost it's electrode, do you mean it is dirty or has been so hot it melted off. If the ground electrode is missing than you have a bad injector, running very lean or the wrong heat range of plug. Have you changed the wires? If your wires are good I would do a cylinder leak down test only after I checked the output of the coil pack. Also bad valve guides will leak oil down and foul plugs if you use a high ash content oil. My advice is to take it to a good Ford dealer and have them look at it. Oh, how about the intake o rings have you checked them? Lots of things to check, good luck.
R> Hi! I have a '96 Explorer with the 4.0 V6. I've had my spark plugs
The ground electrode is gone - not sure whether it melted off or ???
The last time they changed the plugs, the mechanic checked for lean condition by injecting propane to cylinders. He said the this was not the problem - how does this test work?
Also, I'm still wondering which cylinder is number 4. Driver's side front?
Thanks, ...Jerry
Jery, #4 is passenger side front, F O 1-4-2-5-3-6. Try this test, one gallon milk jug full of water, pour water over the intake manifold with the engine idling and see if it changes speed. This test is for the manifold 0-rings. If #4 cylinder melts the ground electrode you have one of the following: bad injector, o-ring leaking or wires crossed. Check your coil pack, wires #1 and #5 hook to the same coil pack, I think, Jim W. check me on this ok. If wires are ok than it has to be 0-rings or injector problems. What plug do you use, AWSF 22P or what? Again my best advice is take it to a good Ford Dealer. Your Explorer must have about 130,000 miles by now so all kinds of strange things can go wrong than can only be tested with the proper test equipment, ie Ford Dealer or other good shop. Good luck and please advise what you find out.
R> The ground electrode is gone - not sure whether it melted off or ??? >
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