[jedipimp]

Hiya Guys,

Recently I have experienced the sputtering, stuttering, hesitation that plagues the focus. I have a 2001 SPI manual. It has 89k km on it.
I have searched and read through every thread on the subject here, and I have been trying to use the info to try and solve this problem. However, I have a not been successful and I'm hoping someone could shed a little more light on the my situation.

I have,

-Replaced the fuel pump/filters ( done at dealership under the warranty) I did this last fall.
-Replaced spark plugs, checked the coil pack/wires. All looks new.
-done the EGR/DPFE tricks from focus hacks.
-Used a OBD-II and it come's up clean. (never had a check engine light)

None of these things have helped. I suspect a vacuum leak, maybe O2 sensor, MAF? I dunno, but before I started down that road, I wanted to ask one question with one added bit of info.

After the fuel pump was replaced, it did not stop the sputtering. However, it was just before winter. The weather quickly got cold. All winter, it ran tip top, not a single time it sputtered. living in Alberta, the weather gets quite cold from Oct to March. Come this spring, it's warmed up and it is now sputtering again.

First, I only drive 11km to work. 22km a day. It's been this way for pretty much the entire life of the vehicle.
The car starts fine. It idles great. The only time it starts sputtering is about 1km from work, literally 2 mins before I'm done driving it. Some days I think If I had to drive another extra Km, it would die. After work, I get in start her up and it runs and idles great, drives great, right until I'm about 2 mins from home. At this point it's about to die. The idle is rough, it'll have a big stumble every 5-10 secs or so and there is extreme hesitation when accelerating and the sound fromt he exhaust is micro back fires, buhhhhuphphpphphphpphphphhp. If I hit a red light near that time, my car almost stalls out. I have to keep the RPM up manually while sitting at the read light in fear it's gonna stall.
I make it home and I turn off the car. The next day, again starts fine, drives great until almost at work, rinse and repeat.

I have since found a solution to stop it from doing this... although it's not much of a solution, more of a band-aid. I hope from this info can lead some expert around here to what my problem is.

Turing the AC on fixes the problem. It's an odd reversal of the a/c stutter bug some of our cars get. My car runs perfectly with the a/c on. No rough idle, no hesitation, besides from the normal a/c being on hesitation, no sputtering. What would cause my car to run better and fix the sputtering/rough idle/hesitation when the a/c is turned on?

Thanks in advance for the help, it's very appreciated.

[konafocuswrc]

exhaust leak??possible clogged catalyc converter?
or intake filter is dirty and possible sucks in hot air.

[darkpuppet]

Sounds like it could be a vacuum leak, or a MAF issue.

I'd try cleaning your MAF, and if you can, get a reading on your vacuum. I would almost bet it on being your MAF... it might be just dirty, or the heating wire on it is faulty.

[ZTWsquared]

(05-31-2011, 05:52 AM)darkpuppet Wrote: Sounds like it could be a vacuum leak, or a MAF issue.

I'd try cleaning your MAF, and if you can, get a reading on your vacuum. I would almost bet it on being your MAF... it might be just dirty, or the heating wire on it is faulty.

If turning the AC on fixes it, wouldn't it have something to do with idle speed adjustment ... idle air control valve maybe? Wouldn't that also be consistent with cold idle fine, hot idle bad?

[moon111]

Check the EGR tube where it connects to the exhaust manifold. They like to leak or break there. Some I've read worry that it will cause a poor fuel/air mix, causing excess heat and lead to a valve seat problem.

[Mystake]

(05-31-2011, 07:41 AM)ZTWsquared Wrote:

(05-31-2011, 05:52 AM)darkpuppet Wrote: Sounds like it could be a vacuum leak, or a MAF issue.

I'd try cleaning your MAF, and if you can, get a reading on your vacuum. I would almost bet it on being your MAF... it might be just dirty, or the heating wire on it is faulty.

If turning the AC on fixes it, wouldn't it have something to do with idle speed adjustment ... idle air control valve maybe? Wouldn't that also be consistent with cold idle fine, hot idle bad?

This gets my vote.

[NOS2Go4Me]

(05-31-2011, 07:41 AM)ZTWsquared Wrote:

(05-31-2011, 05:52 AM)darkpuppet Wrote: Sounds like it could be a vacuum leak, or a MAF issue.

I'd try cleaning your MAF, and if you can, get a reading on your vacuum. I would almost bet it on being your MAF... it might be just dirty, or the heating wire on it is faulty.

If turning the AC on fixes it, wouldn't it have something to do with idle speed adjustment ... idle air control valve maybe? Wouldn't that also be consistent with cold idle fine, hot idle bad?

Yup, check this. I've heard of this on a few Foci. It's an age thing, not a mileage thing.

[jedipimp]

Hi all, just wanted to give an update.

Thanks for all your suggestions and quick responses! I wanted to give an update sooner, but it's been fairly cool the last week or more and I haven't drove the car much so I was uncertain my issue was fixed.



It seems to be fixed.

I checked for a vacuum leak, I checked the MAF. When I checked the MAF, I did so at friend of mine, fathers shop and while we were looking at it one of the mechanics walked over to see what we were doing. He asked if we needed help. I explained what I was checking. When he looked at the MAF he looked confused and asked if I had already replaced it. He was surprised because he says it looks brand new, not a day used. In fact even the surrounding tube etc was spotless not a spec of dust. Right away he said this does not look right for a 10 year old MAF sensor/housing and and says he thinks little or no air is coming through , so took off my air filter...
Yikes.







There was 100's of these little seeds.. or whatever the hell they are, completely lining the bottom of my air box, on top of that, there was a cm thick blue/green pocket lint type material (seen in the first pick) lint covering the back of my air filter. ( I missed taken pic of air filter )

This upset me as I was told by the dealership that this had been replaced just 8 months prior. The guy says there is no way this is an 8 month old build up. The guy's theory was that when the engine warmed up to operation temperature the air being provided was not enough to keep it running smoothly as it does when it's first ran from being cold. Either way, all cleaned up , new filter in and on my way.

This did not fix my problem.
But this next part did!

Okay, so the next day I'm ready to start diggin into the engine. I give it another once over for the usual suspects to see if I missed something before I go out and get the engine runnin all hot and produce my engine failure. I check the plugs, wires, hoses etc. Nothin.

So I go driving around and 20 mins later bam, engine barley staying alive. I take it back home into the garage and pop the hood while its running, stumbling like crazy and nearly stalling.
WTF is that! I notice something is different. My engine is making a clacking/clicking noise.
I get nice and close and find out that the noise is coming from my spark plugs. This was definitely not happening only 25 mins ago. Under closer inspection, I was able to see what I was hearing. It was an electrical arc between the plug and the wire. as seen in the video below. I could see the wire moving with each arc and when I touched the wire, it stopped.





So, I turned the engine off and decided to pull the wires/plugs. and this is what I found.





These came right off when I pulled the wire plugs off the spark plugs, they crumbled right off. The metal wire inside crumbled to the touch.

Needless to say, I placed some brand new spark wires on, the arcing sound went away and the engine is running great when hot. No more idle/stumbling/hesitation problems!

Now, this is one of the first things I checked. It's one of the very first things that anyone tells you to check when you have the symptoms my engine had. However, with the whole "works fine when cold, runs like crap when hot" promoted for a different diagnosis.

I was a little confused as to why I did not find this problem before, as I checked the wires at least 4-5 times prior, but I have a theory.

Every time I checked them in the past, they were cold. The engine was cold. This was my mistake.
The wires and wire plugs get hot after awhile! They heat up like the rest of the engine. While cold, the metal in the wires and the metal socket connector on the coil wire where the spark plugs snaps into is tight. When the engine gets hot, so do the wires/plugs and the connecting socket. At this point it's warm enough for the metal to expand, creating a loose connection between the spark plug and the wire, creating a gap forcing the electricity to arc at that point. This is also why the wires didn't just pull out so easy when I checked them in the past, the rubber of the wires were cold and held together better and I was unable to see the corroded ends. I'm sure pulling the corroded wires on and off 4-5 times probably helped loosen them up.

Sorry bout the long winded update, I just wanted to touch base and provide as much info about my problem so it may help others in the future.

Thanks again for all your responses and help! The community here is a always very helpful and the forums contain a plethora of very useful and helpful information.