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Discussion Starter #1
Hey there, everyone. I've been stalking the forum for a while trying to find someone else with my problem and a solution but no dice yet so I figured I'd better go ahead and sign up so I could describe my issue.

Anyway, I have an '05 V6 Automatic with no mods. After changing spark plugs, the car suddenly started sputtering/hesitating/backfiring unless I wait for the engine to idle down after cranking it. If I allow the engine to idle down before shifting into drive, the symptoms appear to go away entirely, except when going up a very slight grade and also when accelerating out of a curve. This happens at any throttle and RPM level. On the inclines, it WILL work through it if you punch the accelerator forcing the car to immediately downshift from overdrive. There was never a CEL until today. Had the codes pulled (P0316 and P0303) which are crank sensor condition and a misfire in cylinder #3. Checked for arcing from plug wires and checked fire at coil pack and spark plug. Wire appears to be good. I can feel the #3 fuel injector clicking, though possibly stronger than others. (Going to check the resistance levels tomorrow.) This car runs like it's flooded if you start it up and drive away immediately and never clears up until you turn it off and start it up again (at which point you have to wait for it to idle down, bare in mind). And by immediately I mean unless you wait a literal 3 minutes for it to idle down. When you crank it, it idles at 1500 and after 3 minutes will idle down to about 900. Also, the gas mileage is horrid (went from getting 20-22mpg to about 15mpg city or highway). It's really perplexing and driving me nuts. Anyone have any experience with this sort of problem? Thanks in advance!

**Addition: This may be completely unrelated but I've also been inexplicably losing a reservoir full of coolant in a matter of a few days. Checked all hoses but can't find a leak! I don't know what's going on...
 

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Check the Number 3 plug and the wire. You either cracked the plug upon install, or possibly messed up the wire when you pulled it off. You might not of gotten #3 wire back on either, but I will bet that you cracked the plug upon install. You might of messed up the gap also. If you get #3 corrected, you might reset the codes and see if the crank position sensor code stays gone. If it comes back, you may need to replace the sensor. Good luck.
 

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Question? You said it started backfiring and such after you changed the plugs. Any chance you got 5 and 6 backwards? They are different at the coil and some people get those reversed occasionally. Just a thought. After rereading your questions and what you had done, you may need to replace the C/S sensor. I missed the part about idle down time and such. Selective reading I guess. It gets that way when you get older. :) Check your thermostat housing as they have a notorious problem with them cracking and leaking. Good luck.
 

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Discussion Starter #4
Thanks for the replies! Unfortunately, it was none of this. I even replaced the coil pack this afternoon. No change, in fact, it's even worse now AND I'm out another 70 bucks.

Quick note, though, when I changed the plugs, they were gabbed at .70! I gabbed the new ones at .54 (which is what Autozone told me was stock). Could this have anything to do with what's going on? Why would the original owner have gabbed theirs at .70? 'Bout ready to take a sledgehammer to it.... Any help is greatly appreciated! *sigh*
 

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Luna, unfortunately at places, such as AutoZone some of the employees really have no idea what they're talking about. Best bet would be to to check with ford themselves to see what there recommendation is, as far as the gap. Also, when changing your plugs did you spray anything on them to break the old ones free?
 
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