Idle fluctuation FIXED - Ford Truck Enthusiasts Forums



1999 - 2003 7.3L Power Stroke Diesel SPONSORED BY:

Idle fluctuation FIXED

Reply
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 12-21-2012, 05:31 PM
SBFD8's Avatar
SBFD8 SBFD8 is offline
Senior User
Thread Starter
 
Join Date: Apr 2003
Posts: 185
SBFD8 is starting off with a positive reputation.
Idle fluctuation FIXED

I have a 2000 F350 4x4 CC with the 7.3.
Sometimes when it is idling my idle will go up to about 900 then drop to about 5 or 600 then back up to normal idle about 750rpm I have no idea why it does this. I have changed the air filter, oil, fuel filter, and checked for water in the fuel still it does this from time to time. It does it if I am in stock mode or any HP mode. Any suggestions would be appreciated.
Thanks Al

Last edited by SBFD8; 12-26-2012 at 07:25 PM. Reason: Fixed It
Reply With Quote
  #2  
Old 12-21-2012, 06:12 PM
snakedoc's Avatar
snakedoc snakedoc is offline
Ford With Out Tax Money
 
Join Date: Jan 2009
Location: AL, Reform
Posts: 3,982
snakedoc is a splendid one to beholdsnakedoc is a splendid one to beholdsnakedoc is a splendid one to beholdsnakedoc is a splendid one to beholdsnakedoc is a splendid one to beholdsnakedoc is a splendid one to beholdsnakedoc is a splendid one to behold
i might check the ipr nut.
how many miles on the truck?
Reply With Quote
  #3  
Old 12-21-2012, 06:28 PM
Tugly's Avatar
Tugly Tugly is offline
I'm a cautionary tale
 
Join Date: Jan 2011
Location: Central Washington
Posts: 15,819
Tugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputation
IPR nut, IPR sticking, ICP sensor... these are common issues popping up right about now on this age of truck.
Reply With Quote
  #4  
Old 12-21-2012, 07:02 PM
SBFD8's Avatar
SBFD8 SBFD8 is offline
Senior User
Thread Starter
 
Join Date: Apr 2003
Posts: 185
SBFD8 is starting off with a positive reputation.
idle

I have 262,000 miles I had just replaced the ICP but it was doing this before
and Thank you for the replies.
Al
Reply With Quote
  #5  
Old 12-21-2012, 08:24 PM
1fixitman's Avatar
1fixitman 1fixitman is offline
Elder User
 
Join Date: Aug 2012
Location: Augusta, GA
Posts: 905
1fixitman has a very good reputation on FTE.1fixitman has a very good reputation on FTE.1fixitman has a very good reputation on FTE.
If the ICP is new....ish then it sounds like your IPR is STICKING SHUT and HPO pressure is building just briefly enough to send more fuel than desired. Either raising HPO pressure or increasing Pulse width on the injectors briefly will cause it to raise RPM. Are you having any transmission issues? If you have an automatic and the flexplate is cracked.........that is a large stretch so I am going with IPR.
Dwayne
Reply With Quote
  #6  
Old 12-21-2012, 09:38 PM
Tugly's Avatar
Tugly Tugly is offline
I'm a cautionary tale
 
Join Date: Jan 2011
Location: Central Washington
Posts: 15,819
Tugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputation
Quote:
Originally Posted by 1fixitman View Post
If you have an automatic and the flexplate is cracked.........that is a large stretch so I am going with IPR.
Dwayne
Can you tell me more about this? I never heard of this and I don't understand how the flexplate comes into play. Lope? Slow rise and fall on the idle?
Reply With Quote
  #7  
Old 12-21-2012, 10:21 PM
SBFD8's Avatar
SBFD8 SBFD8 is offline
Senior User
Thread Starter
 
Join Date: Apr 2003
Posts: 185
SBFD8 is starting off with a positive reputation.
idle

No trans problems.
It is really strange does not do it all the time but that is actually what happens does not always go as high but will jump a 100 rpm then down then back all happens with in a couple of seconds.
Reply With Quote
  #8  
Old 12-21-2012, 10:31 PM
1fixitman's Avatar
1fixitman 1fixitman is offline
Elder User
 
Join Date: Aug 2012
Location: Augusta, GA
Posts: 905
1fixitman has a very good reputation on FTE.1fixitman has a very good reputation on FTE.1fixitman has a very good reputation on FTE.
If the flexplate cracks and lets the transmission loose then the engine will really overspeed. It would be similar to running an engine without a transmission attached. NO LOAD whatsoever. It would be a ten million in one chance that it could happen. Mostly I wanted him to focus on an IPR that has 262K on the clock.

I would have said to look for leaky up pipes but that would lead to less boost and the RPM going low....not high. But he probably does have leaky up pipes....it is just not contributing to the high blip on the idle. Merry Christmas and Happy the World Did not end day LOL.
Reply With Quote
  #9  
Old 12-22-2012, 05:36 AM
Tugly's Avatar
Tugly Tugly is offline
I'm a cautionary tale
 
Join Date: Jan 2011
Location: Central Washington
Posts: 15,819
Tugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputation
Thank you for that, I learned something new.

As for the idle, how many miles on your oil and what type is it? The IPR is new-ish, but a lying Injector Control Pressure sensor can do weird things. Inspect your ICP Sensor, it is in the picture below, just above the "T" on the T-500, near the very top of the photo. Inspect it for leaking oil or a bad/dirty connector. Check the nut on the IPR (straight left of the "T" of the T-500)... that nut is so flimsy it can work its way loose.

Reply With Quote
  #10  
Old 12-23-2012, 12:54 AM
SBFD8's Avatar
SBFD8 SBFD8 is offline
Senior User
Thread Starter
 
Join Date: Apr 2003
Posts: 185
SBFD8 is starting off with a positive reputation.
The icp sensor is new I will check ipr.
Thanks
Reply With Quote
  #11  
Old 12-26-2012, 07:24 PM
SBFD8's Avatar
SBFD8 SBFD8 is offline
Senior User
Thread Starter
 
Join Date: Apr 2003
Posts: 185
SBFD8 is starting off with a positive reputation.
Fixed it

Thanks to all that replied you were right I found the problem.
THE IPR NUT HAD FALLEN OFF SO THE PARTS WERE MOVING.
Put it back on and it is perfect.
I think I am going to replace the IPR just to be safe.
Once again Thanks
Al
Reply With Quote
  #12  
Old 12-27-2012, 06:33 AM
Tugly's Avatar
Tugly Tugly is offline
I'm a cautionary tale
 
Join Date: Jan 2011
Location: Central Washington
Posts: 15,819
Tugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputationTugly has a superb reputation
Congrats! The best-priced fix: Free. IPRs aren't cheap, so that gets replaced only as needed.
Reply With Quote
  #13  
Old 12-27-2012, 07:20 AM
Christof13T's Avatar
Christof13T Christof13T is offline
Postmaster
 
Join Date: Apr 2012
Location: Victoria, Tx
Posts: 2,520
Christof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant futureChristof13T has a brilliant future
even then...
a quick teardown and cleaning of the ipr generally clears up sticking issues... easy peasy to do and again... no buckzooka ammo required.


and now is as good a time as any to remind about the passenger side fuel line. its not a bad task if you pull the cac tube from the spider on that side for wiggle room.
its not pretty when that line finally wears through... easier to prevent it than deal with the aftermath of 55-70psi diesel fuel spewing all over your engine compartment.
Reply With Quote
  #14  
Old 12-27-2012, 08:53 AM
SBFD8's Avatar
SBFD8 SBFD8 is offline
Senior User
Thread Starter
 
Join Date: Apr 2003
Posts: 185
SBFD8 is starting off with a positive reputation.
Thank you for the info



UOTE=Christof13T;12643063]even then...
a quick teardown and cleaning of the ipr generally clears up sticking issues... easy peasy to do and again... no buckzooka ammo required.


and now is as good a time as any to remind about the passenger side fuel line. its not a bad task if you pull the cac tube from the spider on that side for wiggle room.
its not pretty when that line finally wears through... easier to prevent it than deal with the aftermath of 55-70psi diesel fuel spewing all over your engine compartment.[/QUOTE]
Reply With Quote
  #15  
Old 12-27-2012, 01:38 PM
SBFD8's Avatar
SBFD8 SBFD8 is offline
Senior User
Thread Starter
 
Join Date: Apr 2003
Posts: 185
SBFD8 is starting off with a positive reputation.
fuel

I am not familiar with the passenger side fuel issue can you explain. Thanks
Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
throttle body stuck in limp mode danerisfree 1999 to 2016 Super Duty 3 05-19-2016 12:20 AM
fuel loss chad 95 f350 1994.5 - 1997 7.3L Power Stroke Diesel 32 05-20-2013 12:15 AM
limp mode ? bootlakeman 6.0L Power Stroke Diesel 8 11-02-2011 05:52 PM
2006 f150 4.6 misfire / rough idle paultfh 2004 - 2008 F150 3 12-02-2009 04:00 PM
cannot pull codes laserred 1987 - 1996 F150 & Larger F-Series Trucks 1 02-02-2006 10:36 PM


Go Back   Ford Truck Enthusiasts Forums >

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

Forum Jump


All times are GMT -5. The time now is 04:52 AM.


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. FordŽ is a registered trademark of the Ford Motor Company.