F150 troubles (starts, doesn't start, starts, doesn't start ...)

Thanks in advance for reading the verbose story that follows.

Today in the bank the friendly teller asked me how my holiday was.

“Well,” I started as a pithy - yet accurate - comment came to mind. I finished by telling her “our truck broke down before, during, and after our trip.”

Several weeks ago we began noticing a little weakening in the acceleration of our beloved 2004 F-150 from about 45-52mph. If you feathered the accelerator just perfect through that range you wouldn’t feel anything, or if you were in a higher gear (such as climbing a hill).

Then a couple weekends ago it just wouldn’t start. We had it towed to our mechanic’s and he diagnosed and replaced the fuel pump. $650 or so out the door. This was immediately after spending $70 to get the winter studded tires put on (legal through the end of April). So far: $720.

Then - 8 days ago (Dec 20) on our way out of town - the truck began running really rough. We had about 450 miles over two days to traverse, and the first leg (about 300 of the miles) was pretty rugged. The truck ran, but it was definitely misfiring. And we were getting the blinking “service engine soon” light on the dash.

Saturday morning (Dec 21) I went straight to an Auto Zone, only to find out that California outlawed code checks at retail stores about 5 years ago. A friend of ours lives in the town where we’d stayed the night before so after checking a couple other mechanics and oil change facilities (most of them closed), I was able to stop by there and make some calls from his house since he knew the lay of the land. We ended up lucking out with an employee at a local tire shop who heard my request for a code check and said “I’ll help you out.” He spent about 15-20 minutes with the truck, read the code as Coil #2, happened to have a brand new coil in a toy box of his in the garage, and when I asked what I owed him he said he was just there working for cash that day. I handed him the $30 that was in my wallet and thanked him very much for his time.

The next day (Dec 22) the truck ran without trouble.

On Tuesday (Dec 24) I was going to run to the nearby town. The truck not only had a flat tire, but was turning over without starting. This was the same thing that happened before the fuel pump needed replacing. At least as far as a lay-person could tell from behind the wheel.

We were 10 miles from town and I was getting ready to have the truck towed in. As a last ditch effort, though, we tried jumping it with my stepdad’s mid-90’s truck. It worked. He had an air compressor, too, for the tire. I was glad he was so prepared (kind of a necessity, though, as they live in the Sierra Nevada at about 5000’ elevation).

At the nearby Les Schwab, the tire repair was free, and a new battery ran $127 including tax and a $10 install fee (we’re up to $847 for the truck now).

On Thursday (Dec 26) we drove about 170 of the 400 miles back home. No issues.

Yesterday (Dec 27) we drove the remainder of the distance home. No issues.

Today I loaded up the kids to give the wife some time to turn the house around for tomorrow’s company.

Turns over. Does not start. I tried jumping it with our '95 Windstar. No dice.

WORTH NOTING:

  • I whole-heartedly trust our mechanic. He showed me the (original) fuel pump that he took out and it was pretty nasty. He even cleaned out the bottom of the tank from all the residual silt and grime from 225,000 miles’ worth of fill-ups. I don’t mind opinions on the necessity of this repair, but I am not really questioning this.
  • we acquired the truck from my mom (where we also happened to be staying the majority of this recent trip). She’d driven it from 60k to the ~220k it had when we got it last summer. Lots of TLC, but I did learn from the “under the table” mechanic that the plugs were factory (he explained the brush of paint on the top of the plugs that gave this fact away).
  • the battery was definitely weaker last Tuesday when it ended up needing a jump. Today the battery was strong but it would only turn over (not start)

Any suggestions? Should I go after a tune-up before trying to diagnose further? I’m thinking about getting all 8 COP’s + the plugs themselves. I’ve never changed COP’s before, but I did pull a couple of them a couple weeks ago before the fuel pump got fixed. Didn’t seem too difficult, though I know a couple of them are tougher to reach than most. I don’t want cheap COP’s if they aren’t good quality, but I definitely want to save money where possible. Between the truck and a recent radiator repair for our van, we have dropped $1006 in repairs into our vehicles this month.

If the plugs have 220K on them, they’re screaming to be replaced

You can measure the coils with an ohm meter and see if any are out of spec. Plugs need changing BAD. I would start there. Is your check engine light on?

“If the plugs have 220K on them, they’re screaming to be replaced”

…and its a miracle that it is ever running half-way well at all. And after 10yrs and 220K be prepared for potential disaster. Don’t try to remove them hot or warm.

Start by replacing the plugs. You then need to determine if the no start issue is due to an ignition or fuel delivery problem. Spray some starter fluid into the intake and see if that gets the engine fired up. If so then check the fuel delivery system for a problem. Something like the fuel pump relay might be bad. I doubt the pump is at fault since that has been already changed out.

@Cougar - thank you! The starter fluid got it going. The fuel pump and fuel filter are both brand new, but this at least helps isolate the trouble. Still going to get the plugs replaced post-haste, but I’m also keeping a canister of starter fluid handy.

You’re welcome for the help. Hopefully the trouble is just a bad relay.