decelerating - 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 09-11-2009, 07:02 PM
Member
 

Join Date: Apr 2009
Location: Hanford, CA
Posts: 32
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
decelerating

Ok, this may be a dumb question, but this is the first Powerstroke I've owned..

When you decelerate (coast) to a stop sign in the country, it sounds like the engine is actually shutting down part of the time and only firing occasionally. It isnt running bad, and it sound like it is by design..
I was wondering, 1) is that what its doing? The truck has an aftermarker muffler, tailpipe, turbo downpipe, and chip, so you can generally hear the engine pretty well
And 2) if it is doing that, is that a Powerstroke design, or being done by the aftermarket chip... We have no idea yet what chip is in it.. We were told the former (original owner, we're second owners) put a chip in, but no one was sure which one.. If it is doing it, for which ever reason, it definetly helps the deceleration with the horse trailer... This has no exhaust brake, but it controls the decel better than any other diesel I have driven without an ex brake.

And a quick 3)... where is the computer in the '97 CC F350.. I'd like to take a look and see if I can tell which chip is in it, but I dont know where it is on this model.

Thanks
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 09-11-2009, 09:49 PM
Powerstroke.org Fanatic
 

Join Date: Feb 2008
Posts: 102
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
This is totally normal. All 7.3's do it whether they are chipped or not. The engine is not actually shutting down, the injectors just quiet down because of the lack of load and therefore, fuel demand required to keep the engine running. Most of the engine noise that the 7.3 makes is from the injectors firing, so their state of operation ( i.e. how much fuel they are delivering) largely determines how loud the engine is...until the rpm's get in the higher range and other noises such as exhaust and turbo begin to dominate. The ecu is located in the firewall on the driver's side. It can be accessed in two ways. One is from under the hood, but is a pain to get out that way....you have to remove part of the inner fender well, so don't do this unless you need to change the ecu for some reason. The other way and better way since you are just looking to remove the chip for inspection is to remove the three nuts that hold on the parking brake pedal. Push it aside after removing the nuts and you will find a hole behind it which looks right at the end of the computer and therefore, the chip. Good luck!
Reply With Quote Quick reply to this message
  #3  
Old 09-12-2009, 07:41 AM
Emergency Services

 

Join Date: Apr 2008
Location: Beeville, TX
Posts: 1,483
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
That is perfectly normal. The computer quits injecting fuel all together when it doesn't need to. If you are decelerating, and you have your foot off the petal, it will stop all together till the RPM is getting close to idle. It should pick back up before the RPM falls below idle speed.
Reply With Quote Quick reply to this message
  #4  
Old 09-12-2009, 07:52 AM
Super Moderator

 

Join Date: Nov 2008
Posts: 13,275
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 2 reviews
Yep and its not just the 7.3s, the 6.0ls do it as well. Its a pretty cool sound if you ask me
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 10:27 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