Miles? Clogged Fuel Filter could definitely lead to stalling. But I'm willing to bet the injectors could be clogged. I've always use injector cleaner every 6 mo/year to keep them clean. It would make sense that when you give it more gas, the injectors are shooting at a higher pressure, and if they are clogged when it idles that little pressure isn't enough to push it through the small holes that are in the injectors to begin with.

As for recommendations on injector cleaner I just use the standard bottle but I've seen some very broad opinions that span to never using it to some who swear by it.

This should be moved to the problems section, you may get more replies there.

 

Thanks for the reply.
I did want to mention that I did originally suspect the TPS, as lots of people have had issues with this unit.

I did remove it, and tested the continuity, and it is good, closed is 1.6K, open is 4.69K Ohms as far as I can remember. I am getting 5VDC from the PCM.

Fuel injectors? It does seem somewhat related,

How does this get moved to the problems section?

 

There can be so much that really does go into idling so your car doesn't stall. Your ecu could be damaged to the point where it forgets the idle process/throttle body/injector or fuel system just off the top of my head. Mod has to move the thread, GapBoyPCS, I believe is in charge of modding this forum.

 

try cleaning the throttle body and maf sensor

 

The "Problem" Section is a general catch-all for issues. Most likely, the more "specific" issues get move to Team Tech. Us moderators and administrators will move threads/topics if it's warranted.

How many miles are on your car? What engine is in your car?

As for the issues being faced, it can be a lot of things. If you've recently replaced something, then double check things are on tight (like vacuum hoses and spark plug wires). A clogged fuel filter could cause driveability issues as well. An OBD-II scanner can go so far in diagnosis. If it's getting that bad, maybe you need to have a shop or dealership look into the issue with more complex diagnostic computers.

 

The car has about 217K on it, The MAF sensor looks clean.
It has the DOHV Zetec engine.

The idle is one thing, but the whole miss and bog thing is what causes me to think that it is something more serious than a filter.

I am preparing myself to drop the thing off at a shop, but have gone through this process before (for a separate issue) and they had a hard time finding the problem, replacing every part that they could think about at my expense.

Do you think that this IACV is a possibility?
(It is mounted under the throttle body?)

 

Just an update, no extra work done on the car yet, but on the way home I decided to put in a bottle of Gunk Injector Plus Cleaner.

After about 5km, it seems like it is getting better.
I wonder if this has all stemmed from a bad batch of fuel.

For any Ontarians out there, the last place that I got fuel was the ESSO on the South 400, just north of TO.

 

It may have. That being said, I've had mixed issue with Esso myself.

I only use Sunoco or Petro Canada. But that's just personal preference.

I'd just keep an eye on it. IF you have never done the fuel filter, it may be time to start I replace mine every 50,000 km

 

It could just be funk built up in your fuel system, probably a good idea to do the filter. I don't know anything about gunk injector plus I imagine its just as good as any other fuel system cleaner. You might also want to look into a product called seafoam. It can be used in gas tank, intake manifold, and oil and my experience was good. Search here or online in general.

 

Just came back from another 25km test drive.

Runs great at 1/2-Wide Open throttle, but always had.

Sometimes, it is working normal. Then, all of a sudden, just like Dr. Jeckle and Mr. Hyde it starts doing this weird low RPM stumble again.

It is Pissing me off to be honest. What in Gods name could this be?
I think tomorrow, I will install a new Fuel filter, then monitor it over the weekend. If it still acts up, I will have to look for a good shop somewhere in Newmarket.

One thing, on the drive tonight, 2 codes popped up.
They are

PO136 O2 Sensor Circuit malfunction Bank 1 Sensor 2.
P1131 lack of HO2S Switch Sensor indicates Lean

I have replaced both O2 Sensors, so is this misleading or direct to the point?

 

Double check that you haven't kinked any wiring and/or connections are tight on the sensors first. If any codes are coming up for any issue, it can be the part itself AND/OR something connected to that system.

 

does it work well at high engine RPM? just bogging from a stop and / or low engine RPM?

when was the PCV valve last changed? its easy to change, $5 part

 

Johnny, thanks for the reply.

Yeah, thing works OK in the upper 1/2-full throttle range, as long as the bog has cleared out.

No, I haven't changed the PCV valve, the store didn't have it in stock the other day, otherwise it would be on my list of replaced parts.

Is it worth while trying?

It just seems like it is flooding itself or something at low RPM, then, you need to tromp on it to clear it, then it is OK, until it drops back down in RPMs.

I have just been looking on Craigslist, interesting. Damn, I might be better just to buy another one, that is working....for under 3K.
I just don't want to spend 1K on parts, searching for something that isn't there. I have already dropped 300 on miscellaneous parts and pieces, wondering when to call it quits at the home garage.

Is a fuel regulator something that needs to be looked at?
Seems like the IACV works, because IF it is idling OK, when I turn on the AC, it wants to tend to up the idle. So, it would appear that that is working.

One thing, last night I tried is I ran the car without the breather tube, and the mass flow meter installed. It actually ran better, then quit. But restarted easy. I am totally miffed.

Tomorrow, I will pick up a PCV valve at Canadian Tire.

 

well if the car runs better with no MAF, then its safe to say there is an issue with the MAF. Its an expensive part that's not refundable, but it sounds like that might be worth doing.

The PCV valve is a really simple job, and if it hasn't been done its worth doing just because its so cheap and easy.

The only other thing I can think that would throw a code like you're getting is a vacuum leak. It would make sense that it would work better at full throttle. On the Zetec, the PCV system vents back into the back side of the intake manifold. If you look for it, its a rubber elbow about 4" down from the throttle body. That hose has a tendency to collapse and then break. SO with the car running, listen for an air leak by the intake manifold. Then move your hand around and feel each of the hoses coming from the back side and see if it makes any noticeable change to sounds, etc. The crushed hose should be easy to identify then.

 

Johnny, thanks again.

I am about to go out and get the PCV valve.

I don't know if you saw above, but I already replaced that really soft vacuum hose on the lower side of the throttle body.
The new hose is a little harder than the original.
(And yes, the original was collapsed, and had been I assume for a long time)

Is there any way to detect a vacuum leak?
Like a spray or something that rev's up the motor or anything?
It is such a hard thing to work on buried in the back like that.....

 

Replaced the PCV component, didn't change.
I cannot get the bolt off of the fuel pump retainer to the frame, otherwise I would have replaced the fuel filter as well.
It seems to be an 8mm. Tight.

Looks like I will be limping this thing to a shop on Monday.
Thanks for all of the support people, I am usually pretty good at this....but this one has me thinking that it is not something obvious.

When it gets fixed, I will let everyone know what the result was.

Thanks again,

 

Problem Solved

Within an hour, the local mechanic down the street at MIDAS was able to determine that the cause of my problem was a vacuum leak, located beneath the Throttle Body Intake tube, (spoken about in this forum before..the one that kinks).

It is apparently a port that is on both the SOHC and the DOHC TBI, But, the orfice is CAPPED in the DOHC. The port is used on the SOHC model. The cap had somehow freed itself, and was causing this leak.

I don't think that I would have ever found this, I am so happy now.

Oh well, I spent some extra money on O2 sensors that wasn't required, but at least the problem is fixed. The diagnostics and repair was $49.95.
I was so happy that I had them replace all of the worn out tires with new Bridgestones.

I will try to grab a pic of the port that I am referring to, and maybe help others in the future.

 

Re: Problem Solved

Within an hour, the local mechanic down the street at MIDAS was able to determine that the cause of my problem was a vacuum leak, located beneath the Throttle Body Intake tube, (spoken about in this forum before..the one that kinks).

It is apparently a port that is on both the SOHC and the DOHC TBI, But, the orfice is CAPPED in the DOHC. The port is used on the SOHC model. The cap had somehow freed itself, and was causing this leak.

I don't think that I would have ever found this, I am so happy now.

Oh well, I spent some extra money on O2 sensors that wasn't required, but at least the problem is fixed. The diagnostics and repair was $49.95.
I was so happy that I had them replace all of the worn out tires with new Bridgestones.

I will try to grab a pic of the port that I am referring to, and maybe help others in the future.

Did you ever manage to get a picture of this port?

I'm having the same issue with mine...but I'm prone to believe the MAF sensor is the culprit. It's thrown up the code for the MAF sensor ...but sometimes it will run just fine...and might run fine for 6 months. Then it will suddenly start skipping and sputtering...the more accelerator that's applied, the worse it gets...turn off, crank up and it's liable to drive for weeks without another skip or sputter....

It's really annoying to have this issue..mine is the DOHC motor, and it's really got me confused. I have no clue what to replace, but I've seen a hint that you could maybe clean the MAF sensor???

Anyone know what you should use to clean it? I'd sure like to avoid this $130 part if I can..that's a high price to pay for something that "could" be the problem...or could be a leak on the vacuum.

 

Future reference, tracking down a vacuum leak is listen/feel, and if that doesn't work, spray brake cleaner around all vacuum lines/intake hoses and listen for a change in idle quality/speed.

 

CRC MAFS cleaner

To clean the MAFS, buy a bottle of "CRC Mass Air Flow Sensor" cleaner, available at many auto parts stores. Just hose it down, but don't touch the filaments with anything (such as a Q-tip). It's in a red and white spray can.

In order to take off the MAFS, it's often recommended you first disconnect the battery [see Tech info for more on this].

Then, you'll need a "safety Torx" bit in a size I forget--these have a little hole in them as the MAFS has tiny "pins" in the middle to keep hooligans (or non-Ford service techs!) from messin' with it. You also have to disconnect the sensor from the wiring harness (pretty obvious how to do that). If you remove the sensor, be very gentle when you pull it out; it is not something you want to handle indelicately.

Or, you can remove the air intake tube (as I do) and sensor in one piece and "shoot the cleaner down the tube".

I just hose the metal filaments down until the cleaner is literally pouring onto the floor. There are several angles you should hit it from, including from the underside.

Give it plenty of time to dry, then replace. **Note: do not "shake it dry!"


Ouila! Cleaned sensor. Gently push it back into its housing, tighten the screws down until they're snug, connect the harness, and reconnect battery.



Hope this helps.

--Scott

 

You can look at O2 sensor output at idle and instantly tell a vacuum leak, there will be no crossover at the switching point of .5 volt. BTDT on 2 Foci and 1 F150. Ford used really crappy vac hoses that bubblegum up and then the side sucks in to make for leaks. Very common problem. On Focus it's the PCV entry way down at back bottom of intake.

 

I'll probably be tackling this same problem this weekend along with replacing the VSS. Thanks for the info.

 

Hi all,

I have owned a 2000 Ford Focus for about 10 years now.
2 days ago, my wife indicated that the car started stumbling while driving to work. She could barely keep it going, at low RPM's. (Automatic)

I have taken the car for a ride several times since, and have discovered that the problems seem to disappear after about 1/2 throttle and up. That is the car has power and works fine until you let off of the gas.

There are no CEL's, and I have an OBDII reader that can clear codes as well.

In reading some of the threads last night, I replaced the following tonight, in hopes of solving this problem.

1. Replaced Both O2 Sensors
2. Replaced Air Intake Filter
3. Replaced 4 Spark Plugs with Autolite Double Platinum plug
4. Replaced the bad Throttle Body/PCV Hose mentioned in threads here
5. Tried the EGR bypass/DPFE thing mentioned here (didn't make any difference)

I was praying that the problems would be gone when I started her, but sadly, I could tell right away that they were still there.
Stumbling and idling very poorly, almost stalling.
If you push the throttle down, you usually can clear it and rev it up, after a heavy bog.

I don't know what else to do.

Years ago the Fuel Pump was replaced, under warranty.
It has a full tank of fresh fuel put in it this morning.
I have not checked the fuel filter, is this a symptom of a bad filter?

Please, if anyone has any information that may be helpful, I would love to hear it.

When you replaced the Throtle body Did you replace the TPS sensor that was on it? if No that is the same problem I had changed TPS sensor on throttle body Problem gone