I have a 1999 Ford F250 Super Duty 5.4L.

Recently, I've noticed something strange. My truck fires up easily and seems to run well, but I'll feel a little bit of a shutter when sitting behind the wheel. It's a really subtle thing, but it's causing me a bit of concern.

The truck will fire up and run no problem. But if I pop the hood and take a look at the engine while the truck is idling, sitting in park, the engine will buck just a tiny bit. I'll be able to see it shake just a bit, and then recover. There's a minor change to the regular hum of the engine while this is happening. It will sound different. After this, the engine will seemingly recover and run fine again. If I were to sit there and stare at the engine, I bet this happens every few seconds. And, it's not like the engine is choking and trying to recover and barely able to turn over after the stutter. It's a really minor thing. It just stutters, sounds different, I see the engine buck slightly, and then its back to normal.

It's not a predictable thing. There's no pattern as to when it happens (not like a single cylinder is misfiring every time). It doesn't seem to make a difference if the engine is hot or cold, and the vehicle isn't throwing any codes. I have no problem accelerating or revving the truck up. While driving, aside from this little shutter, which i can feel behind the wheel, it seems fine.

Very rarely, while idling (sitting in park), the engine will die. But, after it dies, I'll just turn the key and it fires right back up again.

I'm stumped as to what kinds of thing this could be. Anyone have any thoughts? Does this sound like anything familiar?

I appreciate everyone's help. If I can clarify further, in any way, just ask!

Thanks!

 

I have a 2003 f 250 with the v10 it does the same thing really annoying. Had missfire code changed c.o.p the code went away but truck still did it couldn't find vacuum leak changed my p.c.v valve nothing then I cleaned mass air flow sensor and it stoped for a few weeks now it's back again not showing any codes

 

I had issues like this in a Ranger 2.3L, but not with my 5.4 F250.

Things that immediately come to mind are:
the idle air control valve sticking
fuel injectors need cleaning or replaced
spark plugs need cleaned and re-gapped or replaced

If for some reason it may run a little deeper than that, @ametzker did a really nice budget rebuild on his F250. As a part of this he pulled the cylinder heads and had a valve job done and replaced the lash adjusters because they were collapsed. Here is the post after he got them back from the machine shop. He also replaced gaskets and and a few other parts.

https://www.ford-trucks.com/forums/1...l#post16183443

Here is the video of it running after it was all put back together. I am not sure how it sounded before, but it is smooth as honey after the valve job.

 

Quickest and easiest thing to try is cleaning the thorttle body. Seen it work before on an 04 SD with 5.4.

 

Finally got a chance to work on this truck a little bit more.

I tried cleaning the throttle body (it was very dirty) and the MAF sensor with no success. I'm still having the same problem. So I'm still struggling with what's wrong.

Here's a few other things I noticed:

Right when I start the truck up, and the engine is cold, the engine doesn't stutter. But once everything is warmed up (after maybe 10 minutes of idling) the stutter I described before becomes a lot more pronounced.

I held the engine at 2000RPM instead of the usual 800-1000RPM at idle. When at 2000RPM the issue doesn't appear to happen. The engine sounds normal and runs smoothly.

When idling, and the engine is stuttering on and off, it seems like I get little coughs and puffs out of the exhaust every time it stutters.

Does this sound like an injector issue? To me, I wouldn't expect something to be wrong with an injector if at 2000 RPM it seems to run normally. Am I thinking about this the wrong way?

 

I'm having literally the exact same issue on my v10. I took out the IAC valve and cleaned it thoroughly and reinstalled it, that briefly solved the problem but now the gremlin is back. I've ordered a new IAC valve from Rockauto and hope this solves the problem.

Edit: any time I'm on the as it runs great, it's only at low RPMs and idling I have a grumble

 

Has the fuel filter ever been changed?

If the injectors are dirty with a poor spray pattern, I could see that being a problem. Old fuel filter may be the culprit. A dirty injector in my quad made it idle like a Harley. I took it out and cleaned it and the idle smoothed out nicely. I need to do this to my Ranger as well. 223k on the original injectors.... I'd say they've earned a cleaning.

 

It has, I started with the cheap and easy, fuel filter and pcv. I also thoroughly scoured for vacuum leaks. I've got new plugs and coils, so if it's not the IAC I will be removing all the injectors for a good cleaning.

 

I know it is an old thread, but are there any updates regarding the slight stutter?

Thanks!