1999 ford taurus se cyl 6 misfire

dadof2girls20092011 said:

I Have a 1999 Ford Taurus Se. I changed spark plugs and coil pack and I checked compression what could it still be misfire on cylinder 6 .

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Spark plug wire(s), injector?

sheila said:

Spark plug wire(s), injector?

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And in stead of replacing them, you could also interchange them (say injector 6 with injector 4) and see whether the problem moves with it (say P0306 becomes P0304).

Architect said:

And in stead of replacing them, you could also interchange them (say injector 6 with injector 4) and see whether the problem moves with it (say P0306 becomes P0304).

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Yes you should be diagnosing before changing parts. The OP knows that cylinder 6 is misfiring but doesn't provide any more information as to how that is known. Codes are the beginning of a diagnostic not a parts changing instruction.

rjacket said:

Yes you should be diagnosing before changing parts. The OP knows that cylinder 6 is misfiring but doesn't provide any more information as to how that is known. Codes are the beginning of a diagnostic not a parts changing instruction.

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Technically if you change enough parts, you might solve the problem and others you didn't know about

ice445 said:

Technically if you change enough parts, you might solve the problem and others you didn't know about

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As to changing parts. If you have ~100K on plugs, fuel filter, and such, change maintenance items just because that need done and, sometimes it fixes your issue.
After that, do diagnosis. Eyeball is a place to start. And I have found fuel trims need to be checked in routine maintenance.
-chart-

sheila said:

Spark plug wire(s), injector?

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I change them and checked the injector too and still that 306 code

Are spark plug wires 5&6 the right way around?

dadof2girls20092011 said:

I change them and checked the injector too and still that 306 code

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Unlikely, but in theory it could be the injector is not powered. I think you can clearly hear the clicking of the injectors 4, 5 and 6 if they operate properly.

Next step is to do a compression check of cylinder 6. Could be there is a head-gasket leak near cylinder 6. Worst case, there is a crack in the cylinder head itself near cylinder 6.

Did this problem arise just like that, without any obvious cause (such as overheating) or was the problem there since you got the car?

It overheated once but the misfire was there before it overheated. But I'm starting to believe a headgasket [maybe] I drove 12miles without it overheated just the misfire

chartmaker said:

See pic. You can crank it over with no fuel, no ignition with the jumper. My pic G-4, other years might be different.
Listen to the starter pulses, should be 3 pulses (frequency of grind) per revolution. All should sound the same. Minimum of 6 pulses, ok to several rouonds. If there is a skip, you have bad compression on one or two cylinders will skip.
-chart-

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Best with the throttle plate open.
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I had a misfire. It was elusive, swapping plugs and wires and despite using a reader i was getting results that were a bit confusing. Then i swapped coils with what i was sure was a new unknown brand that came with a load of parts i bought. That did not clear anything up, it created more confusion for me. So then I bought a new SMP coil and when i put that in i still had a miss which made me think i had a way more serious issue though i noticed that the miss changed location yet again. I ultimately bought a new motorcraft coil and voila, no more miss, problem gone.

I'll swap the new one out and see what happens thank you

There's a slim chance it could be a broken valve spring. Compression test cranking will pass. I had a 3.0 Ranger that had bad guides causing a misfire. Rule out all options before pulling the head.

chartmaker said:

Best with the throttle plate open.
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Why is that? Preventing over- or under-pressure in the intake?

If the throttle plate is closed, the cylinder does not get a full charge of air, but limited air and thus a very low reading.
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