Turbo randomly runs at minimun duty cycle with no throttle??? - Ford Powerstroke Diesel Forum
Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 09-28-2013, 03:40 PM
Premium Member
 

Join Date: Dec 2012
Posts: 509
Thanks: 0
Thanked 19 Times in 17 Posts
Feedback Score: 0 reviews
Turbo randomly runs at minimun duty cycle with no throttle???

So I've been chasing issue after issue with this 6.0L... I've gotten it to the point where the truck is running good AND THEN...

I first noticed a deep rumble of an exhaust note during idle that cleared (followed by the turbo whistle) after applying any sort of throttle. I looked into the limited PIDs that the SCT livewireTS offers and noticed that during random traffic light stops the VGT duty cycle drops to 11-12% (resulting in zero boost) when normally I would see 44-48%. I don't know if what I am reading on the SCT is the duty cycle commanded by the PCM or actual vane postion. When I accelerate the turbo lights and it returns to its normal 40ish% dc under modest acceleration. Anyone have similar experience with this issue? I'm looking to nip it before it becomes a bigger issue. I want to blame the VGT solenoid or EBP sensor but the SCT shows some wild number for EBP so I can't trust it as a reliable source.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 09-28-2013, 03:54 PM
Powerstroke.org Rookie
 

Join Date: Apr 2013
Posts: 21
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
This is normal behavior. The vanes periodically change position while idling to prevent them from getting stuck. Mine does this too. Sounds like the turbo is turning on and off every 20 seconds or so.
Reply With Quote Quick reply to this message
  #3  
Old 09-28-2013, 04:00 PM
Premium Member
 

Join Date: Aug 2009
Location: Somewhere Between Good and Bad
Posts: 1,409
Thanks: 4
Thanked 13 Times in 13 Posts
Feedback Score: 0 reviews
Quote:
Originally Posted by Beauxroux View Post
This is normal behavior. The vanes periodically change position while idling to prevent them from getting stuck. Mine does this too. Sounds like the turbo is turning on and off every 20 seconds or so.
I was going to say the same thing. It's what the latest strategy does to exercise the turbo and prevent sticking of the unison ring.
Reply With Quote Quick reply to this message
  #4  
Old 09-28-2013, 06:45 PM
Premium Member
 

Join Date: Dec 2012
Posts: 509
Thanks: 0
Thanked 19 Times in 17 Posts
Feedback Score: 0 reviews
I know of the vane sweep... this is while in drive at a stop light. I hear the turbo whistle disappear and it gets a real deep V8 idle. If I watch the SCT it will be 11-12% duty cycle (it does not vary or sweep, it will stay in this state the entire duration of the stop light) when you fuel it, it has a slight hesitation until the SCT reads 39-42% and the turbo lights. It did this to me just about every time I let off earlier in the day. However, I just towed a friends car on my tandem axle trailer for 55 miles and never had any hiccups. Weather temperature related??? Hmmm... I suppose I will wait until the symptoms are replicable. Its hard to trouble shoot something that happens away from home but won't show itself when you have your tools out.
Reply With Quote Quick reply to this message
  #5  
Old 09-29-2013, 07:54 AM
Powerstroke.org Rookie
 

Join Date: Jan 2012
Location: Devine, Texas
Posts: 28
Thanks: 1
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Normal operation. Many variables go into the sweep ( low duty cycle) of the vanes.

Your chasing a problem that doesn't exist IMO.
Reply With Quote Quick reply to this message
  #6  
Old 09-29-2013, 08:41 AM
Powerstroke.org Rookie
 

Join Date: Apr 2013
Posts: 21
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
There's nothing wrong with your turbo. Most Sct tunes have this feature in their strategies, maybe this is why you are just noticing. Mine does this at traffic lights as well. I'll be driving, come to a stop, then hear my turbo "turn off" and get a deep V8 rumble for 20 seconds or so then it'll turn back on and start whistling. Turbo also turns back on once you give it any throttle. I have a straight pipe and I can hear it happening very clearly. People in traffic usually start looking around and open their windows to try to figure out what's going on. There is literally nothing for you to be worried about. I find that it happens more when the weather is hot. It's completely healthy. Like previously stated... You're chasing after a problem that doesn't exist. I admire your concern and determination to resolve issues with your truck before they become worse, this just isn't an issue. Quite frankly, if it wasn't doing this, I would suggest you get your ECM updated to the latest strategy so that it does. All of that worrying for nothing!
Reply With Quote Quick reply to this message
  #7  
Old 09-29-2013, 04:49 PM
Premium Member
 

Join Date: Dec 2012
Posts: 509
Thanks: 0
Thanked 19 Times in 17 Posts
Feedback Score: 0 reviews
Man that's weird. If you're headed down the interstate at 65 and let off throttle it drops to minimum, too? I've had the same program/tune on for 9 months now and never experienced this until yesterday and I watch my parameters religiously. I've always known the truck to sweep the vanes when idling in neutral or park but never in drive or while the truck is moving.
Reply With Quote Quick reply to this message
  #8  
Old 09-29-2013, 09:23 PM
Powerstroke.org Rookie
 

Join Date: Apr 2013
Posts: 21
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
It does it while in drive, yes. It only does it if your RPMs are below a certain threshold.
Reply With Quote Quick reply to this message
  #9  
Old 01-11-2014, 10:45 AM
Premium Member
 

Join Date: Dec 2012
Posts: 509
Thanks: 0
Thanked 19 Times in 17 Posts
Feedback Score: 0 reviews
Just an update. The problem was becoming more frequent. If I apply throttle it stays at 14% (open) and lags like crazy sometimes and run normal others. Eventually it just stayed at 14% and one morning triggered a P0470 code so I replaced the EBP sensor and tube and all is normal again. No annoying lag or random drop in exhaust note and throttle response.
Reply With Quote Quick reply to this message
  #10  
Old 01-11-2014, 05:06 PM
Powerstroke.org Rookie
 

Join Date: Apr 2013
Posts: 21
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Glad to hear you got it figured out.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel 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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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:

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
Display Modes

Posting Rules
You may post new threads
You may 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



All times are GMT -8. The time now is 10:23 PM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors