Hello all,
I've lurked these boards for sometime now and have found what I've been looking for thanks to all of you. Well, this time I couldn't. So here's my issue.

I have a 99' f-250 super duty, 5.4, auto, 4x4, built in Feb of 99'.
Last summer, while pulling my 5th wheel, I noticed some mis-firing or studdering. Nothing terrible, but noticeable. On the way home my abs light came on and the cruise shut off so I pulled over to check things out. Everything looked ok. Got in and the trans wouldn't shift into 2nd gear until 30mph. Took it in and they said a couple sensor's blew. Had them replaced and things seemed fine.
Then the intermitent missing started getting worse. It would run fine for a week or so, then I'd have a day with the mis-firing. Then back to fine. Took it to the ford dealer and of course it ran fine. no codes, no check engine light. Took it home and it started acting up again. Took it back in, had them keep it for a few days and everything was fine. NOT!
Had the 102,000 mile top of line tune up and they said this should take care of any problem. IT DIDN'T. Same problem the very next day. They said they couldn't do anything until the check engine light comes on.

Now it's getting more and more frequent. Still no check engine light, but it should be on!
Gonna take back in to the dealer, but I would like your input or suggestion.

The truck sits in the drive during the week. I Drive It up north and around town. (it happens in the summer/ fall / winter).

Sorry for the long first post. I look forward to your wisdom!!

I did a search and found a post from Tony1790 from dec. 13, 2002. but never really gives an answer.

 

Did they put on a new fuel filter? You may also have water causing a short on a COP.

 

Sure sounds like a coil like hydro said there are eight of them they sit on top of the plugs..They go bad causing skipping. I would take each one out and check em out. Maybe replace boots.


Dick

 

According to the dealer, the tune-up included fuel filters, new plugs and coil packs. injectors and fuel rails cleaned, etc. It was their FULL tune up.

As far as water in the lines..........I thought that too. I've been running some premium gas plus the fuel treatments that remove water (STP / Heet). Same problem.

This has happened in the warm weather as well as the cold. That's why I'm confused.

I was thinking maybe the catalitic (sp) converter possibly? Or would that just over heat and shut the truck down?

 

Is it studdering upon acell or cruising? Cold or hot. If they gave you the full tune with coils that would have cost over $500.00 or more..

Dick

 

the tune up cost me $680.00!!

The truck studders upon both acell and crusing. Sometimes at idle. Cold or warm, it doesn't matter. I guess it's an equal opportunity problem!

The truck ran terrible on Thursday. Perfect all day yesterday!

I just don't get it.............

 

Oh boy! I'm thinking its prob a coil But the dealer already changed them? Or did he?
Is a new one bad? Is it missing just on one cyl? Is it a consistant miss in other words when a coil goes bad you get a consistant dah dah dah dah or is it skipping or hic uping now and then? A bad coil or dead cylinder will do the dah dah dah upon accelleration and also in neutral reving the engine you can tell.

Dick

 

Dick,

I appreciate your trying to help me solve this issue.

It's a skipper! It'll miss for a spell and then "kick in". Then it'll miss again for a spell and then run fine.

Like I stated above. Thursday on a 45 mile trip, it ran bad more than good. Spuddering 80% of the way. Saturday it didn't miss a beat. Ran great! Could the coil be bad intermitantly?

I thought about the dealer not changing the rear plugs or coil packs as well. The plugs in the rear were half the reason I didn't attemt to do it myself. (Along with the possiblity of having a plug blow out if I didn't torque them properly).

I still don't know why the check engine light doesn't come either. Any clue?

 

Normally when you get a tune up and it skips the folks who did the work have to go back in and find out what they did or didn't do. For that amount of cash it should run great. I would have never replaced any COP's just for the heck of it. My 99 still runs great with the COP'S it came with. The dealer should be able to find the problem.You have to get a real mechanic to look at it, thats about all I can tell you at this point.


Good luck!!! Dick

 

When it is sputtering and missin, does it seem like you lost all of your top end power?

 

Thanks!


I've had it back there twice to no avail. It did run fine for a couple month's and I thought the problem was resolved. Until a month or so ago. I'll just have to take it back and hope it acts up while I'm there.

If the issue does get resolved, I'll post the diagnostics here. Maybe it'll help someone else in the future.
This is a very informative site. I'll have to become more active instead of just "lurking".

Thanks again.
-Steve-

 

Redford,


Yes, there's definately a loss of power. I have to hammer the accellerator to get back up to speed.

 

If it were me I would pull all the plugs and look at them and the coils very closely. Maybe a cracked plug or bad boot.

Dick

 

Has anyone checked to see if your catalytic converter is clogged?

 

Has anyone checked to see if you're catalytic converter is clogged?