Duratec engine stumble stutter misfire FIXED - Ford Focus Forum, Ford Focus ST Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Ford Focus Forum, Ford Focus ST Forum > Ford Focus Tech Discussions > General Technical Chat

General Technical Chat This section is for technical discussions relating to general maintenance, electrical issues, engine trouble, and recalls.

Search This Forum | Image Search | Advanced Search    
Ford Focus Tire & Wheels FocusFanatics Merchandise

Reply
 
Thread Tools Display Modes
Old 08-02-2013, 12:36 PM   #1
Marde
Focus Addict
 
Marde's Avatar
 
Join Date: Jun 2013
Fan#: 115991
Location: Mesa, AZ
What I Drive: 2004 ZTW PZEV 2.3 ATX

Posts: 882
FF Reputation: 7 Marde Good Standing Member
Buy-Sell-Trade Rating: (0)
Duratec engine stumble stutter misfire FIXED

UPDATE:
This post was written after I saw my engine stutter problem disappear after replacing a bad PCV hose. The engine stutter problem returned. Replacing the PCV hose did not fix my engine stutter problem. Additional info at post#3.


2004 2.3L ATX with 141K miles.

I do not have a question, but wanted to share a fix and lessons learned.

Quote:
Originally Posted by Marde View Post
<snip> …unique problem with engine stutter only between 35 to 45 MPH & only when barely applying the gas pedal. The problem started and was barely detectable and as time went on (and as Arizona temps got hotter) the problem became more prevalent.
In the last couple weeks, this unique problem also started showing up during light acceleration at slower speeds too, and when it happened, the engine stutter also became worse.

Problem has been fixed. I replaced my PCV and PCV hose. The old PCV seemed good, but I replaced it anyway. The old PCV hose looked very bad and seemed to be split, but did not seem to have a hole in it. The hose has two bonded/molded layers. In some areas, the outer layer had peeled away, but the inner layer was still intact. The inner layer was very very soft and was likely collapsing during the engine stutter problem.

The old and new PCV hose had slightly different part numbers and manufacture date differences.

Old: 3S4G-6758-AC
New: 3S4G-6758-AF

Old: >FKM/ECO<03 6
New: >FKM/ECO<13 3

During the work of replacing the PCV hose, I also replaced my lifetime air filter with a stealth CAI K&N cone filter RC-9160. I am mentioning this because this could have played a role in the problem or in the fix-> My intake air vacuum pressure has likely been reduced because of the K&N filter.

On an unrelated note, I also replaced my thermostat, upper and lower radiator hose.

I could not have done this without FF’s. Thank you everybody.



Last edited by Marde; 08-02-2013 at 06:06 PM.
Marde is offline  
    Reply With Quote
Sponsored Links
Advertisement
 
Old 08-02-2013, 01:03 PM   #2
my_beautious_ZX3
Focus Addict
 
Join Date: Feb 2006
Fan#: 32386
Location: Chicago, IL
What I Drive: 2002 charcoal XZ3

Posts: 745
FF Reputation: 5 my_beautious_ZX3 Good Standing Member
Buy-Sell-Trade Rating: (0)
good job and thanks for sharing the solution!
__________________
"I'm jealous of girls because they get to wear dresses." (Todd Flanders)
my_beautious_ZX3 is offline  
    Reply With Quote
Old 08-02-2013, 06:10 PM   #3
Marde
Focus Addict
 
Marde's Avatar
 
Join Date: Jun 2013
Fan#: 115991
Location: Mesa, AZ
What I Drive: 2004 ZTW PZEV 2.3 ATX

Posts: 882
FF Reputation: 7 Marde Good Standing Member
Buy-Sell-Trade Rating: (0)
Duratec engine stumble stutter misfire -NOT- FIXED

The engine stutter I had was there everyday as long as I duplicated the correct scenario (cruise between 35-45mph with light acceleration). Yesterday I did 2 lengthy test drives to (1) confirm proper operation of my brand new thermostat, check temps and adjust coolant level (2) see if the engine stutter problem was gone. It was definitely & positively gone.

Today’s news is engine stutter problem has returned. I am very sorry for my premature announcement that the problem was fixed. I have updated my first post.

I plan to test TPS voltages next, but it might have to wait a few days. BTW, I have recently replaced spark plugs, plug boots, fuel filter and used a can of injector cleaner in a tank of gas.
Marde is offline  
    Reply With Quote
Old 08-02-2013, 11:07 PM   #4
my_beautious_ZX3
Focus Addict
 
Join Date: Feb 2006
Fan#: 32386
Location: Chicago, IL
What I Drive: 2002 charcoal XZ3

Posts: 745
FF Reputation: 5 my_beautious_ZX3 Good Standing Member
Buy-Sell-Trade Rating: (0)
alright.

I'm not sure exactly what you mean by "stutter", but a failed DPFE can cause oscillating RPM's, which can feel like a hesitation. On my Zetec + ATX, it occurred around 2000 RPM. The oscillation itself is small but noticeable; if I had to guess, plus/minus 100 RPM.
__________________
"I'm jealous of girls because they get to wear dresses." (Todd Flanders)
my_beautious_ZX3 is offline  
    Reply With Quote
Old 09-17-2013, 03:47 PM   #5
Marde
Focus Addict
 
Marde's Avatar
 
Join Date: Jun 2013
Fan#: 115991
Location: Mesa, AZ
What I Drive: 2004 ZTW PZEV 2.3 ATX

Posts: 882
FF Reputation: 7 Marde Good Standing Member
Buy-Sell-Trade Rating: (0)
Two FF’s (amc49 and codices) have PM’ed me on this. Instead of another PM, I am posting my PM reply onto my OP.

Hi guys,
Thanks for your reply. I am unsure if your comments (amc49) were addressed to me or to codices. Not sure how multi/Quotes work in PM’s either. I do not consider my focus problem to be a “misfire” but that word could be used as part of the description. My symptom is best described as 2 separate problems; (#1) hesitation, bog or stumble during light acceleration, a total loss of power/compression-> when at a stop and taking off. I can always recover from this (or prevent this) if I step harder on the gas pedal. This condition is worse or happens more frequent if AC is on. (#2) Surging or bucking <like a bobble head doll> when cruising and barely applying the gas-> This symptom first appeared only between 35 to 45 mph, but has recently also showed up at 15 to 25 mph. I have never seen/felt a problem at highway speeds. Please note that both symptoms above have one thing in common-> happens during light acceleration.

@codices – Like you said, I have never seen these symptoms during my first couple of minutes on a cold engine. I have also seen the symptoms and severity increase "the hotter the car gets"... and more so if during the heat of an AZ summer day. Are you experiencing both symptoms I described above (#1 and #2)?

I had a CEL and P0300 code once and this was before any of these symptoms appeared. I cleared the code and have not seen one since.

Here is a recap of what I have done:
Replaced bad PCV hose. No other vac leaks found/suspected
Spark plugs replaced copper 103’s -gaps set
New fuel filter
MAF is clean and looks new
IACV is clean and I can tell it works based on idle & AC on/off
TPS tests good (full range of motion voltage testing completed)
IMRC solenoids (I have 2 on my PZEV) vac hoses intact and connected to actuators. None of this stuff has been tested or replaced.
Most recent: new set of 4 COPs -coil on plugs & boots

My comments from PM shown below:
I installed my 4 new (COPs) coils ($104.00 via Amazon) a couple days ago. New coils did not fix my stumble/hesitation/bog/bucking/surging problem. With my future plans for this 2004 140K mi car, I am OK with replacing old coils, even if it did not fix my problem. Many many problems <if exactly like this> have been caused by bad COPs. I looked at other Duratec forums (Mazda/Ford truck) and found bad COPs can easily cause this problem.

My next areas of suspicion are; CPS (Cam Pos Sensor) CKP (Crank Pos Sensor), IMRC actuator and solenoid (i have 2 sets of these on my PZEV), Weak Fuel Pump-pressure or Fuel Injectors. 1st up is the CPS and related wiring. I will update my OP-thread about this after my next round... or when I have fixed it.


Thank you for any comments and help.
Marde is offline  
    Reply With Quote
Old 09-17-2013, 08:56 PM   #6
Highball116
Focus Enthusiast
 
Join Date: Mar 2013
Fan#: 112564
Location: Williamsport, PA
What I Drive: 2005 Red ZX4

Posts: 283
FF Reputation: 3 Highball116 Good Standing Member
Buy-Sell-Trade Rating: (0)
Quick question here. I have a 2005 PZEV Duratec 2.0. Do I have two sets of IMRC actuators and solenoids? Often when I'm accelerating, the car starts accelerating slowly, and then it takes off around 2500 RPM, I bet. I don't have a tach, but I think it's around there. I always wondered if that was normal. Does the intake manifold have something to do with that?

Toby
Highball116 is online now  
    Reply With Quote
Old 09-17-2013, 09:59 PM   #7
Marde
Focus Addict
 
Marde's Avatar
 
Join Date: Jun 2013
Fan#: 115991
Location: Mesa, AZ
What I Drive: 2004 ZTW PZEV 2.3 ATX

Posts: 882
FF Reputation: 7 Marde Good Standing Member
Buy-Sell-Trade Rating: (0)
Quote:
Originally Posted by Highball116 View Post
Quick question here. I have a 2005 PZEV Duratec 2.0. Do I have two sets of IMRC actuators and solenoids? Often when I'm accelerating, the car starts accelerating slowly, and then it takes off around 2500 RPM, I bet. I don't have a tach, but I think it's around there. I always wondered if that was normal. Does the intake manifold have something to do with that?

Toby
Hi Toby,

I do not have an answer to your question but let me help remove or add some confusion. The IMRC system has a component that I named "solenoid". I am not sure if the item is properly called a solenoid or not. The solenoid (or two) is located on top of the black plastic intake manifold (IM) and is right in your face after you lift the hood. I also do not know if having 2 IMRC solenoids & actuators is unique to PZEV or not. This old FF picture shows two IMRC solenoids (altho one of them in the pic is mostly hidden by vac hoses) -look at the middle of the picture and find the small copper colored items. Each solenoid has two vac hoses (1) goes into the IM (2) goes to its' own actuator located to the drivers side and mostly underneath the IM.

[/QUOTE]

Also, there is an old thread (or 2 or 3) on FF that talks about engine power loss/slow accel during heat and during loads (AC, lights, stereo). These power losses are/can be normal due to (1) your expectations (2) it's only a 4 cyl Focus (3) engine load (4) other.

My focus is having a problem that is definitely not normal. Your problem might be normal performance under heat/load.

Last edited by Marde; 09-17-2013 at 10:20 PM. Reason: added "-look at the middle of the picture and find the small copper colored items"
Marde is offline  
    Reply With Quote
Old 09-19-2013, 12:31 PM   #8
whynotthinkwhynot
Captain TMI
 
whynotthinkwhynot's Avatar
 
Join Date: Jan 2005
Fan#: 18416
Location: the armpit of TN, Memphis, TN
What I Drive: 05 ZXW; 02 Windstar; 13 C-Max SEL

Posts: 20,128
FF Reputation: 270 whynotthinkwhynot Outstanding Standing Member whynotthinkwhynot Outstanding Standing Member whynotthinkwhynot Outstanding Standing Member
Buy-Sell-Trade Rating: (1)
05 tumble flap actuators are not the same as the earlier D-tecs. Look under the throttle body on the 05 and you'll see an arm and an electric solenoid. That's the tumble flap (IMRC) actuator.
__________________
Be eclectic.
---The Complete How-To Archive--

Moderating everything now, let me know if I can help.

Quote:
Originally Posted by the user formerly known as ZX3_Chick View Post
You're special aren't you.
whynotthinkwhynot is offline  
    Reply With Quote
Reply

Bookmarks & Social Networks
-->
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 07:45 AM.


Copyright 2002-2014 FocusFanatics.com. All Rights Reserved : Terms of Use : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Acura TLX or Fiesta ST. You can find all Ford Focus and Focus ST related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area.