Rough idle and loss of power - Taurus Car Club of America : Ford Taurus Forum
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 17 (permalink) Old 03-05-2017, 12:39 PM Thread Starter
Junior Member
 
Join Date: Mar 2017
Location: TN
Chapter: Southeast
Year: 1996
Model: Ford Taurus
Engine: 3.0L 12v Vulcan V6
Posts: 8
Rep Power: 0
 
Garage
Trader Score: 0 reviews
Rough idle and loss of power

Hey guys Iíve searched this forum and couldnít figure out whatís wrong with my car so I thought Iíd bring up a problem Iím having here. Let me start off by telling you what I have replaced so far.

Replaced:
DPFE Sensor/DPFE hose
Spark plugs and wires
Ignition coil pack
Air filter
Cleaned the IAC
Cleaned MAF sensor

Iím starting to get worried. I have a 2002 Ford Taurus SES with a Vulcan engine. It has a check engine light and it reads codes PO300 which is a random misfire and one time it showed it had a too lean mixture of fuel. I forgot the code unfortunately. It has a rough idle regardless of the gear itís in and if I press the pedal too hard after a stop, the CEL will flash and I will lose a LOT of power. Itíll accelerate at an incredibly slow rate and it wonít return to normal acceleration until it switches gears. I was thinking transmission, but Iíve never had a problem switching gears, it was always such a smooth shift. Strangely enough, once I got the DPFE replaced along with the coil pack and spark plugs and wires, it all returned to normal for about 200 miles. After that, it came right back. It still presents a rough idle and whenever I approach a hill on the interstate, if I press the pedal too much or even if I floor it forcing the engine to accelerate, the RPMs will go up just like normal, however instead of accelerating like it should, itíll decelerate and Iím forced to put my hazards on until it I ease off the pedal to return to normal RPMs once Iíve reached flat road. Iím running out of ideas and the last thing I want this to be is fuel related so hopefully itís not. I replaced the fuel pump and fuel filter about 20,000 miles ago, so Iím unsure if this could still be the problem or not. I have a vacuum leak and have checked the PCV and it all seemed intact. I bought a universal hose from advanced auto parts because I was smelling exhaust in the cabin. I believe itís called the DPFE hose. Itís right above the intake manifold and it wasnít an exact fit, however I used clamps and tape the best I could without restricting air flow and it took away the smell. I do still hear a faint hissing sound below that hose on the right side of the engine, so I know a different vacuum leak is still there, I just havenít found it yet. Surely thatís not whatís causing a loss of power, is it? It isnít loud enough to overtake the engine sound so it canít be that bad of a leak. Iíve ran numerous cars with vacuum leaks and I never encountered these symptoms. Sorry for the long post, I like to add as much detail as I can.
2002fordses is offline  
Sponsored Links
Advertisement
 
post #2 of 17 (permalink) Old 03-05-2017, 02:33 PM
Technical Advisor
 
Join Date: Feb 2007
Location: Milwaukee, WI
Chapter: Midwest
Year: 2005
Model: Ford Taurus
Engine: 3.0L 24v Duratec V6
Posts: 6,198
Rep Power: 75
     
Trader Score: 0 reviews
If you can hear a vacuum leak, it is a big enough leak to keep the engine from running properly...... poor idle, lack of power, etc. Find the leak and fix it. A smoke test would help you locate the vac leak.

05 Taurus SEL Duratec - my daily driver
04 Taurus SES Duratec - wifes car - TOTALED
06 Taurus SE Vulcan - wifes new ride
95 Taurus GL Vulcan winter car
Toy #1 - 86 Tbird 5.0 (original owner) - LOTS of mods
Toy #2 - 88 Tbird Turbo Coupe - LOTS of mods
67 Honda 450 Super Sport - completely customized
Jeff K is offline  
post #3 of 17 (permalink) Old 03-05-2017, 02:48 PM
Play Nice or Don't Play

 
jag1959's Avatar
 
Join Date: Jun 2013
Chapter: Northeast
Year: 1998
Model: Ford Taurus SHO
Engine: 3.4L Yamaha V8
Posts: 13,178
Rep Power: 108
       
Trader Score: 0 reviews
^+1
And do it sooner rather than later, an active misfire can destroy cats in not time at all.
jag1959 is offline  
 
post #4 of 17 (permalink) Old 03-05-2017, 09:09 PM
Crazy Devoted Member
 
Join Date: Dec 2006
Chapter: Midwest
Year: 1998
Model: Mercury Sable
Engine: 3.0L 24v Duratec V6
Posts: 18,810
Rep Power: 99
     
Trader Score: 1 reviews
Fwiw, you must use the proper sized heat resistant silicone hose for the dpfe sensor. Universal vacuum hose will collapse/melt. There are 2 different diameters for the HI and REF ports. Available at most part stores and Rockauto online.
sheila is offline  
post #5 of 17 (permalink) Old 03-06-2017, 10:24 AM Thread Starter
Junior Member
 
Join Date: Mar 2017
Location: TN
Chapter: Southeast
Year: 1996
Model: Ford Taurus
Engine: 3.0L 12v Vulcan V6
Posts: 8
Rep Power: 0
 
Garage
Trader Score: 0 reviews
I did replace one small hose behind the intake manifold with a universal hose from advanced yesterday because it was ripped at the edge but unfortunately it didn't help much at all. It had a pretty thick coating, but no red heat resistant insulation inside like the original one did. I believe it will hold up, but what are some common hoses that could be leaking? I can still hear a leak, but I can't figure out where. And with that fuel mixture being too lean, is it more likely for it to be a fuel pump/filter problem, or more of a fuel pressure regulator problem? I'll try and post a video of me driving the car here shortly.
2002fordses is offline  
post #6 of 17 (permalink) Old 03-06-2017, 10:33 AM
Sam
breeves002

 
Sam's Avatar
 
Join Date: Sep 2012
Location: St. Louis, MO
Chapter: Midwest
Year: 2008
Model: Mercury Sable
Engine: 3.5L Ti-VCT V6
Posts: 6,625
Rep Power: 95
       
Garage
Trader Score: 8 reviews
I'm assuming you are looking at your LTFT to see that the mixture is lean? That is due to the vacuum leak. It is very unlikely there is anything else going on. The cylinders are getting more air then the computer has knowledge of. When it looks at the oxygen content in the exhaust gasses (O2 Sensor does this) it determines there is more oxygen then there should be in the exhaust. To correct that it will add more fuel. This sounds funny because its running "lean" yet the computer is adding more fuel. It can only do this up to a certain point though and then is when it runs lean and you get your P0171/174 codes.

System too lean = too much oxygen in exhaust. System too rich = too little oxygen in exhaust. The PCM compensates by adding or removing fuel as needed.

Sam

2016 Ford Mustang GT Premium
2014 Ford Focus Electric
Moved On:
2008 Mercury Sable Premier
2000 Sable LS Premium Duratec
1997 Mercury Grand Marquis GS
Sam is offline  
post #7 of 17 (permalink) Old 03-06-2017, 02:58 PM
Crazy Devoted Member
 
Join Date: May 2011
Location: NY State
Chapter: Northeast
Year: 2003
Model: Mercury Sable
Engine: 3.0L 24v Duratec V6
Posts: 7,535
Rep Power: 85
      
Garage
Trader Score: 0 reviews
Quote:
Originally Posted by sheila View Post
Fwiw, you must use the proper sized heat resistant silicone hose for the dpfe sensor. Universal vacuum hose will collapse/melt. There are 2 different diameters for the HI and REF ports. Available at most part stores and Rockauto online.
Might I add?

Pic of the mounted style DPFE, and hoses, they are not red but more robust than vacuum hoses. The 'stand alone' style of DPFE uses a much more robust hose and are red inside. They are nearly rigid as they support the sensor which is not fastened to anything but the hoses.

My take based on OE parts. My '01 had the stand alone style but my '03's are mounted style, bolted to the rear head.

-chart-
Attached Thumbnails
Click image for larger version

Name:	DPFE17.jpg
Views:	23
Size:	59.9 KB
ID:	188538  
chartmaker is online now  
post #8 of 17 (permalink) Old 03-06-2017, 05:12 PM
Devoted Member
 
Join Date: Jan 2010
Location: North Canton, Ohio
Chapter: Midwest
Year: 2006
Model: Ford Taurus
Engine: 3.0L 12v Vulcan V6
Posts: 4,217
Rep Power: 52
   
Trader Score: 0 reviews
My 1993 used gray silicone hose without any reinforcement braiding in them. I bought the replacement from Ford and was like $13 for six inches. I seem to remember the 1993 may have use one hose because it was a pressure sensor and not a differential pressure sensor, but that was 16 year ago.
Automender12345 is offline  
post #9 of 17 (permalink) Old 03-06-2017, 08:27 PM
Crazy Devoted Member
 
Join Date: Dec 2006
Chapter: Midwest
Year: 1998
Model: Mercury Sable
Engine: 3.0L 24v Duratec V6
Posts: 18,810
Rep Power: 99
     
Trader Score: 1 reviews
^+1. Single hose was probably the older pfe sensor.
sheila is offline  
post #10 of 17 (permalink) Old 03-07-2017, 12:55 PM Thread Starter
Junior Member
 
Join Date: Mar 2017
Location: TN
Chapter: Southeast
Year: 1996
Model: Ford Taurus
Engine: 3.0L 12v Vulcan V6
Posts: 8
Rep Power: 0
 
Garage
Trader Score: 0 reviews
So far I haven't been able to find the vacuum leak, but I did have a question. Why is it that whenever I first start the car and it's completely cold, the idle isn't rough, and I have the amount of power that I should have? But whenever the car warms up, it goes back to having all these issues?
2002fordses is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Taurus Car Club of America : Ford Taurus Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
2004 Ford Taurus rough idle, loss of power, codes jumping Taurusaurus237 Maintenance and Repair 16 12-22-2016 10:25 PM
Rough Idle and loss of power. Powerthantos Maintenance and Repair 5 05-22-2016 11:17 AM
1986 LX Rough Idle when cold now no Start kpeters Maintenance and Repair 1 03-23-2016 06:31 PM
Random stalling/bucking loss of power pinball-mark Maintenance and Repair 15 05-19-2015 08:03 AM
05 Taurus: Misfires, rough idle, power loss under load, cats low after AIM replacemen Rkcmore1 Maintenance and Repair 2 02-24-2015 06:32 PM

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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome