Ford Enthusiast Unofficial Resource

Go Back   Ford Forum - Enthusiast Forums for Ford Owners > General Ford Forums > General Tech
Sign in using an external account
Register Forgot Password?
Search


Welcome to Ford Forum!
Welcome to Ford Forum,

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!


Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 06-28-2012, 07:39 AM
Junior Member
 
Join Date: Oct 2011
Posts: 29
Default HELP!!!! rough idle

here is my problem. when my 97 f150 5.4l truck is at idle i get a rough idle. almost feels like it wants to die. i have replaced the EGR valve, the Mass Air Flow sensor, the Idle Air Control valve and the DPFE sensor. when i first noticed the problem i had a MAFF code come up, then just yesterday i had a 1401 code (DPFE). About 2 months ago i had the catalytic converters on the drivers side replaced at Meineke. they used two of their universal cats because it was a lot cheaper. before having the cats replaced i had an O2 sensor code but the mechanic said it was probably because i had holes in the cats. so after replacing all these parts i am still getting the rough idle. can anyone please help?
Reply With Quote
  #2  
Old 06-28-2012, 08:55 AM
Senior Member
 
Join Date: Sep 2011
Location: Thunder Bay, ON, Canada
Posts: 161
Default

Would the roughness go away if you step on the gas just a bit (to rev the engine to about 900 rpms)? Do you get misses and hesitations while driving normally, or the engine runs great EXCEPT for idling?

Let us know, and good luck!
Reply With Quote
  #3  
Old 06-28-2012, 04:55 PM
Senior Member
 
Join Date: Sep 2011
Location: Iowa
Posts: 709
Default

I assume your ignition parts are new as well?

You could also idle it for let's say 10 minutes and after letting it cool off pull the spark plugs. The look of the spark plugs could tell you if you have a miss fire on one particular cylinder and many other possibilities.

Did you run a few tanks with fuel system cleaner?

Did you check for vacuum leaks?

From what I gather there were a few parts thrown at it based on the codes. The codes don't replace proper old fashioned diagnostics.
__________________
Bluewind

"It is important to know the difference between 'precise' and 'accurate', even if you are neither!"

Our family vehicles:
'03 Ford Windstar
'00 Ford Contour SE, 2L
'98 Mazda Protege, 1.5L 5 speed
'97 Mazda B 2300
Previously owned:
'94 Ford Aerostar XLT 4L, '89 Geo Prizm , '86 Mazda 323 DX, 5 speed, '86 Chevrolet Cavalier, '81 Mercury Capri I6, VW 1302, Peugeot 304 (2), VW 1300, BMW R26 (motorcycle), Hercules MK 4 (Moped)


Reply With Quote
  #4  
Old 06-29-2012, 09:18 AM
Junior Member
 
Join Date: Oct 2011
Posts: 29
Default

cougarfan: yes the roughness would go away if i give it gas. runs great while driving.

Bluewind: just had new splitfire E3 plugs put in it about 4 months ago and i have checked for vacuum leaks, none to be found. today it sounds like the engine is loping, just cleaned the K&N filter thinking it may of had too much oil on it and also cleaned the MAF. guess i am going to run some fuel cleaner through it and see what happends. if you guys can think of anything else please feel free to let me know, otherwise thanks very much for reading and replying.
Reply With Quote
  #5  
Old 06-29-2012, 03:13 PM
Senior Member
 
Join Date: Sep 2011
Location: Iowa
Posts: 709
Default

I do not trust the E3 plugs. I am thinking they put up a lot of hype without scientific proof of their claims. I would definitely look at them. Every Haynes manual has color pictures to help with interpretation.
I am not terribly familiar with your engine. The Windstar engine has Intake Manifold Runner Controls that open the short intake runners above 3000 rpm. If they don't close properly they can cause rough idle. There are small plastic grommets on the linkage of the control. These grommets brake and get lost. If your engine has IMRC that's a place to look.
Fuel injected engines have also a cam synchronizer that can go bad.

But honestly I would keep driving rather than throwing parts at it.
__________________
Bluewind

"It is important to know the difference between 'precise' and 'accurate', even if you are neither!"

Our family vehicles:
'03 Ford Windstar
'00 Ford Contour SE, 2L
'98 Mazda Protege, 1.5L 5 speed
'97 Mazda B 2300
Previously owned:
'94 Ford Aerostar XLT 4L, '89 Geo Prizm , '86 Mazda 323 DX, 5 speed, '86 Chevrolet Cavalier, '81 Mercury Capri I6, VW 1302, Peugeot 304 (2), VW 1300, BMW R26 (motorcycle), Hercules MK 4 (Moped)


Reply With Quote
  #6  
Old 07-05-2012, 05:24 PM
Senior Member
 
Join Date: Sep 2011
Location: Thunder Bay, ON, Canada
Posts: 161
Default

Quote:
Originally Posted by iuecbrad View Post
cougarfan: yes the roughness would go away if i give it gas. runs great while driving.
I'd check for vacuum problems - such leaks are obvious (and annoying) when the engine idles (and diminish or go away when you step on the gas) because the leaked air flow with the throttle plate closed is comparable to what the IAC valve lets in, thus throwing your idle all over the place. But there may very well be other causes I'm not aware of ...

Good luck, and let us know how it goes!
Reply With Quote
  #7  
Old 07-05-2012, 09:30 PM
Senior Member
 
Join Date: May 2011
Location: Colorado, near Denver
Posts: 670
Default

Best way to diag this is with a scanner; look at the time-adjusted long term fuel trims for both banks after it enters closed loop (usually only take about a minuet, tops to enter it). If the LNGFT1 and 2 are off by more then 10 percent (either way), you have something to look for (too rich, look at fuel system for correct pressure/delievery; too lean, vacuum leaks).
One other note: I've done driveability for longer then fuel injection has been around, and the O.E. plugs really are the best in most instances; Ford has spent a ton of money designing plugs that promote the best burn characteristics that you can get for the engine, while still keeping within Federal guidlines for misfire tolerances. Just food for thought.]
On the other hand, I remember I couldn't even diagnose a set of bad plugs and wires on Cougar Fan's car, so, take it with a grain of salt. I'm not there!
Reply With Quote
  #8  
Old 07-06-2012, 06:10 AM
Senior Member
 
Join Date: Jun 2010
Posts: 4,998
Default

Boy, don't remind me of the bath we took with cougar-fan's car. It was indeed a repeat learning experience. After you get burned enough, you learn, and I agree 100% stick with OEM parts by all means.
There is a lot of hype out there for aftermarket stuff. Not all, but most are poor quality imported junk and a good example of "You get what you pay for" !
Reply With Quote
  #9  
Old 07-06-2012, 02:39 PM
Senior Member
 
Join Date: Sep 2011
Location: Thunder Bay, ON, Canada
Posts: 161
Default

Quote:
Originally Posted by greasemark View Post
[...]
On the other hand, I remember I couldn't even diagnose a set of bad plugs and wires on Cougar Fan's car, so, take it with a grain of salt. I'm not there!
Dear Greasemark and Hanky: please don't go hard on yourselves, you know your stuff darn well, and your advice here is invaluable. We all got carried away when diagnosing my car's problem , at the end of the day it turned out to be a great learning experience and an exemplary team work. I don't have enough words to thank you two and Hayapower for helping me get to the bottom of that issue. That's why we're here, to think and share our thinking for the benefit of those in need.

Cheers,
cougar_fan

Last edited by cougar_fan; 07-06-2012 at 02:57 PM.
Reply With Quote
  #10  
Old 07-06-2012, 03:03 PM
Senior Member
 
Join Date: Jun 2010
Posts: 4,998
Default

Thank you cougar-fan for your kind words. I have , but one problem now, my hat got too small!!
Back to the problem iuecbrad has, We all seem to be in agreement that there is a vacuum leak that is affecting the engine at idle. The problem is to locate it.
I'm not positive that this is a 5.4 engine, could it be a 5.8 ?
There are a couple of ways to try to locate a vacuum leak. Of course the ideal way would be to smoke test it. That equipment may not be available so another method might be to pinch off all the vacuum lines you can find one at a time and see which one if any causes a change in the idle quality. To supplement this you might try spraying carb/choke cleaner to areas you cannot access too easily. If it is a 5.8 there are loads of vacuum lines and hoses to search. This is one of those problems where perseverance pays off. It could be something like a worn throttle shaft on the throttle body. As long as the spray doesn't get close to the intake hose it should help to locate the leak. What do you think guys?
Let's hope it isn't a valve problem.

Last edited by hanky; 07-06-2012 at 03:06 PM.
Reply With Quote
Old 07-06-2012, 03:03 PM
 
 
 
Reply

Tags
3000, 94, 98, aerostar, cougar, driving, ford, hot, iac, idle, manifold, rough, rpm, runner, sticking, valve, wont

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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


Advertising
Our Sponsors
Vendor Directory
New Sponsors
All times are GMT -5. The time now is 03:00 AM.

© Internet Brands, Inc.


This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor Company.

SEO by vBSEO ©2010, Crawlability, Inc.