01 Taurus code 0304 miss in cylinder 4

[hakebros]

2001, 3.0 engine, 134,000 miles...showing code 0304.. changed plugs but still chugs. Good spark so I don't think it's wires but that was next. Thinking maybe the coil block. Any suggestions. Cleared code and has not come back yet but miss fire still there...I'm sure the code will come back until corrected.

[sfontain]

I would change the wires anyway. And it could be your coil pack, but I would start with wires nonetheless.

[hakebros]

I got good spark between the wires & each section of coil pack, so I don't think it's that. Give me another suggestion before I change those out.

[joe92k1500]

Could also be a miss due to the injector sticking. Had this on my 01 taurus w/ vulcan v-6. Plugs and wires were changed, did nothing. Injector changed and problem solved. You can try a bottle of Chevron W/Techron concentrate, but I'm not sure if that would help at this point. A new injector may be in order.

[hakebros]

did you hear of moisture under coil block as a potential problem also. especially after a deep detail of engine.

[sfontain]

Originally Posted by hakebros

did you hear of moisture under coil block as a potential problem also. especially after a deep detail of engine.

Yeah absolutely. That's why you're not supposed to spray water on your engine.

[joe92k1500]

Well now that you mention moisture, i read a few posts a while back that mentioned moisture in the plug boot causing a misfire. You can try drying it with a hot hair dryer for a few minutes, and then make sure you put Di-electric grease in the boot. This stops moisture from comming in and is non conductive so spark cant travel out of the boot. Try this on both ends of the plug wire.

[th30n3th3ym1ss3d]

Quote:
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Could also be a miss due to the injector sticking. Had this on my 01 taurus w/ vulcan v-6. Plugs and wires were changed, did nothing. Injector changed and problem solved. You can try a bottle of Chevron W/Techron concentrate, but I'm not sure if that would help at this point. A new injector may be in order.

Originally Posted by joe92k1500
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I would try that before you do anything else and you can also if you have a Digital Multi Meter hook it up to the injector for #4 with the car running and see if you get volt readings at all this way you get rid of the chance of wiring problems.

[jt3]

Strange....I have a '01 SES with same problem...reading 0304 (# 4 cyc. misfire) but all cycl. have very hot spark.. How much trouble is it to change the injector? BTW out on the highway power is way down as if even more cycl. are dropping off but code only shows # 4 .... ???????

[shorod]

There is a threshhold for setting a misfire code. I don't remember the exact numbers, but it is something like 256 misfires detected in 1028 revolutions of the engine. So, yes, you could be experiencing misfires on more than one cylinder on the highway under load, but not enough to set additional codes.

-Rod