Problem: P0316 Misfire code / P0301 Cylinder 1
126k mi
Engine would rough idle, especially under load like AC or in drive with brake depressed. Stutter when going up hill after down shift.
First problem was rough idle in park. This was due to a leak and collapse of the IAC tube under the UIM. The rubber elbow joint that leads into the IAC had worn and collapsed onto itself under vaccume. Second, to fix the misfire, replaced spark plugs and wires. Wasn't the solution, but the plugs were original so it needed that anyway. Final solution was replacement of the Coil Pack. All of these repairs required partial removal of the UMI for access to 1-2-3 plugs and the coil pack.
Resolution: Replace coil pack ($93 Advance Auto Parts), IAC tube (Ford Auto $28)
Lastly, I'd like to thank all the posters in the repair forums. I'm not a mechanic, nor that inclined to engine work, but after reading the multiple entries on this site as to what to expect and how to remove the UMI, it was a breeze. Thanks to all for giving me the confidence to take this on without having to pay over $600 for what was a simple repair. I hope this post can help the next guy.
126k mi
Engine would rough idle, especially under load like AC or in drive with brake depressed. Stutter when going up hill after down shift.
First problem was rough idle in park. This was due to a leak and collapse of the IAC tube under the UIM. The rubber elbow joint that leads into the IAC had worn and collapsed onto itself under vaccume. Second, to fix the misfire, replaced spark plugs and wires. Wasn't the solution, but the plugs were original so it needed that anyway. Final solution was replacement of the Coil Pack. All of these repairs required partial removal of the UMI for access to 1-2-3 plugs and the coil pack.
Resolution: Replace coil pack ($93 Advance Auto Parts), IAC tube (Ford Auto $28)
Lastly, I'd like to thank all the posters in the repair forums. I'm not a mechanic, nor that inclined to engine work, but after reading the multiple entries on this site as to what to expect and how to remove the UMI, it was a breeze. Thanks to all for giving me the confidence to take this on without having to pay over $600 for what was a simple repair. I hope this post can help the next guy.