So last week driving around I was approaching a red light and the truck died on me. It started right back up, and I made it home without it dying again, but every time I came to a stop the RMPs would drop to 300 or lower. It's a 2004 with the 4.6L with 116,000 miles. I've always maintained the truck well.

I Spent some time on the forums reading about similar problems and possible solutions.

I replaced the fuel filter the other day hoping to get out easy, but RPMs were still dropping when coming to a stop, and it died a few more times.

Next up was cleaning the Thottle Body and MAF Sensor. While I had those off (not that it made much difference) I threw in some new Motocraft platinum plugs and boots. I also decided I'd change the oil and replace the air filter.

Just finished everything up today... I'm not certain what fixed the problem, but I don't have any more issues with low RPMs or the truck dying.

Didn't really have any problems, but I have a few lessons learned and some noteworthy comments:

1) The driver side rear plug must be related to my mother-in-law, because it was an absolute b***h!!!

2) When I pulled the boots from the middle two plugs on the passenger side, they were covered in a brown soot. I was able to pull both of those plugs without the wrench... I only used an extension on the socket and was able to turn it by hand. Not sure if any one else has had similar encounters.

3) 1 can of throttle body cleaner and 1 toothbrush was not enough. I had to make another trip to the store to get one more of each. It took one to do the throttle body and the other to do the 90 degree plenum thing behind it.

4) Had to make another trip to the store to get a security torx bit to remove the screws for the MAF Sensor.

5) I used a spark plug socket with a magnet in it(auto-zone) and an 9" extension to start the threads on the plugs. I didn't have a hose handy, but I thought this method was fool proof.

6) Be careful when unbolting the EGR Module. The gasket fell out and down between the intake ports. I couldn't see it, much less reach it, even with a grabber thing and a telescoping magnet. It was metal, and looked like copper, but I will probably never see it again. Yet another trip to the store for a $2 replacement gasket.

7) Next time, I'll buy the small sockets needed for the coils, thottle body, and plenum in a 3/8" drive. All I had was 1/4" drive in this size (7mm,8mm and 10mm i think)

8) I did the plugs with the fuel rails on. It would be easier without them, but I don't know if the trouble of removing them would be worth it.


The truck is running better now than I can remember. The idle has smoothed out, and throttle response seems to be better. I'm anxious to see if my gas mileage will go up at all?

 

Hey.

This is an EXCELLENT post!

Thanks for the very informative and enjoyable read!

Good job!

 

I gained 2 mpg when I did my 100k tune up on my 01 4.6 screw. I thought the plugs would be a nightmare but they really weren't that bad for me. For what the shop was gunna charge me i got everything plus new tools.

 

Yeah, I couldn't be happier with the whole situation. The plugs were much easier than I anticipated. I only spent about $175 for everything including the handful of new tools I got to buy. Who knows what the dealership would have charged me for everything.

 

Just for giggles, I asked them concerning my '08 4.6 and they quoted me at $479. They said the SPS-493 plugs were $22 a piece, but I found them at AZ, O Reilly's and NAPA for $3.49 per plug.