Go Back   Ford F150 Forum - Community of Ford Truck Fans > Late Model F150s > 2004 - 2008 Ford F150
Sign in using an external account
Register Forgot Password?


Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
Old Yesterday, 07:55 AM   #1
Junior Member
 
Join Date: May 2014
Posts: 20
Mentioned: 1 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default Correct RPM's at idle

I have a 2004 with the 5.4L and after the engine is warmed to operating temp, when I am sitting at a red light with the truck in gear, my rpm readout is between the 500 and 750 marks on my tach. I have been trying to figure out this slight rough idle under the condition above, and I have just about come to the conclusion that 625 rpm's is just too low. All I can figure is the PCM is telling the engine to idle at 625. When I manipulate it to 750, all is smooth. Do any of you have the same situation? Does anyone else agree that my rpm's are too low. I have done everything I can think of such as change out plugs and COP's, cleaned MAF sensor, cleaned throttle body, new clean air filter, etc. The only thing I haven't checked is for a vacuum leak, but I don't think that is the problem. Is there any way short of buying a programmer that I can adjust the rpm's up enough to get rid of this slightly rough idle when stopped and in gear? Is there a specific rpm the engine should be under this condition?
xrider is offline   Reply With Quote
Old Yesterday, 08:16 AM   #2
I am Mr. Clean!
 
djfllmn's Avatar
 
Join Date: Jun 2012
Location: York, PA
Posts: 7,363
Mentioned: 6 Post(s)
Thanks: 12
Thanked 276 Times in 220 Posts
Feedback Score: 1 reviews
Default

have you checked that little foam gasket around the filter tray? that has been known to cause trouble
__________________
2014 F150 XLT Supercrew 5.0 (ALL the options)
1968 Ford Thunderbird 2dr Landau 429CID V8 1 of 950-Weekend Toy
DD-1992 Olds Cutlass Ciera
TRADED: 2007 F150 Supercab 5.4
SOLD: 2003 Ranger FX4 4.0 V6
djfllmn is online now   Reply With Quote
Old Yesterday, 08:27 AM   #3
Junior Member
 
Join Date: May 2014
Posts: 20
Mentioned: 1 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Yes I did. AAMOF, I'm the one that drug that thread up from 2007. Definitely made the engine sound better, but no effect on the idle. Do you know what the correct rpm's should be? Maybe I need to take it to Ford and have them reflash the PCM.
xrider is offline   Reply With Quote
Old Yesterday, 08:27 AM   #4
I am Mr. Clean!
 
djfllmn's Avatar
 
Join Date: Jun 2012
Location: York, PA
Posts: 7,363
Mentioned: 6 Post(s)
Thanks: 12
Thanked 276 Times in 220 Posts
Feedback Score: 1 reviews
Default

mine idled around 700-750 IIRC
__________________
2014 F150 XLT Supercrew 5.0 (ALL the options)
1968 Ford Thunderbird 2dr Landau 429CID V8 1 of 950-Weekend Toy
DD-1992 Olds Cutlass Ciera
TRADED: 2007 F150 Supercab 5.4
SOLD: 2003 Ranger FX4 4.0 V6
djfllmn is online now   Reply With Quote
Old Yesterday, 08:36 AM   #5
Junior Member
 
Join Date: May 2014
Posts: 20
Mentioned: 1 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Thanks, that's the kind of info I am looking for.

Anyone else care to share what their 5.4 3 valve idles at?
xrider is offline   Reply With Quote
Old Yesterday, 08:52 AM   #6
Junior Member
 
Join Date: Oct 2014
Location: Maryland
Posts: 11
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Mines Idling around 500 to 650 and yes its just a bit rough. I almost didn't notice.
Ratsan_Fratsan is offline   Reply With Quote
Old Yesterday, 04:25 PM   #7
Junior Member
 
Join Date: Jul 2014
Posts: 15
Mentioned: 0 Post(s)
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Default

My '05 FX4 idle around 550-600 and it sucks because it feels like it's going to miss every couple seconds. It seems to drive just fine though and no CELs I just hate how rough it idles so I've been pulling my hair out trying to figure out what's wrong.
ajack is offline   Reply With Quote
Old Yesterday, 06:58 PM   #8
Senior Member
 
jetchaser's Avatar
 
Join Date: Feb 2012
Location: St. Louis area
Posts: 447
Mentioned: 0 Post(s)
Thanks: 21
Thanked 11 Times in 11 Posts
Feedback Score: 0 reviews
Default

Mine used to idle at 550-625 and I didn't like it. I did the foam repair and it helped a little. I ended up with bigger tires and an Edge Evo--and adjusted my idle to 675 which is way better. Like you, I tried to research and do anything to bump up the idle without any good results. Sorry, but the EVO was my only solution. (but so worth it!!!)
__________________
I Love the smell of Jet Fuel in the morning.05 SCrew FX4. 2" Level with Bilstein HD shocks. 295/70/18 Nitto Trails. Powdercoated Pro Comp Alloy's. Edge Evo. Raptor Nerf Bars. Extang solid fold tonneau. Avital remote start.
jetchaser is offline   Reply With Quote
Old Yesterday, 07:31 PM   #9
Senior Member
 
Join Date: Feb 2014
Location: Pearland, TX
Posts: 538
Mentioned: 2 Post(s)
Thanks: 11
Thanked 13 Times in 13 Posts
Feedback Score: 0 reviews
Default

My 4.6 does this at 650 but on rare occasions it will idle at 700-725 I line it when it's up in the 700 range as it seems it has a little more kick off the line
08silverbullet is online now   Reply With Quote
Old Yesterday, 07:45 PM   #10
Senior Member
 
Join Date: Jun 2014
Location: Martinez, Georgia
Posts: 150
Mentioned: 0 Post(s)
Thanks: 1
Thanked 7 Times in 7 Posts
Feedback Score: 0 reviews
Default

Mine idles between 550 and 650, no rough idle though. I did fix the weather stripping around the airbox about 750 miles ago, fixed the noise I had but idle stayed the same.
vintageman is online now   Reply With Quote
Old Yesterday, 07:45 PM
 
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Join F150 Forum

 

The Mustang Source
All times are GMT -4. The time now is 08:19 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2006 - 20011 F150forum.com
This site is in no way affiliated with the Ford Motor Company.