96 7.3 idles rough at times and "shuts down hard" - Ford Powerstroke Diesel Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 18 Old 10-14-2011, 04:05 PM Thread Starter
Powerstroke.org Fanatic
 
jemorgan3's Avatar
 
Join Date: Aug 2010
Posts: 94
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 8 Post(s)
Feedback Score: 0 reviews
96 7.3 idles rough at times and "shuts down hard"

just bought my first diesel and have been catching up on routine maintenance the previous owner didn't do.. its a 96 7.3 5 speed.

first problem, stumbling at idle: the truck will idle fine for a few minutes, then it will start stumbling and act like its going to stall, but it never does. it will correct itself, then start stumbling again at random intervals. if you touch the gas it smooths out and picks up rpms without skipping a beat and never stumbles when you place a load on it.

second problem: when you shut the engine off, it is a lot louder than any other diesel ive heard, ending with a loud bang, and sounds like its discharging air or sucking air at some point under the hood. i know a diesel engine can,, well, "diesel" on shutdown but this is a little exaggerated.

we chased a fuel leak around the valley of the engine, replacing all the short fuel lines, the mechanical fuel pump and changing the fuel filter in the process. the leak was finally found to be the banjo bolt on the back of the fuel pump, fixed.
jemorgan3 is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 10-14-2011, 04:30 PM
Compression Ignition Addict
 
Patrick Feeley's Avatar
 
Join Date: Oct 2011
Location: Tehachapi, CA
Posts: 2,228
Thanks: 0
Thanked 87 Times in 85 Posts
Mentioned: 0 Post(s)
Quoted: 5 Post(s)
Feedback Score: 0 reviews
Many times those symptoms are due to a bad Dual Mass Flywheel (DMFW). They were problematic on the OBS trucks. You can check yours (to see if it still has one too) by removing the flywheel inspection cover. If the flywheel has dampening springs in the flywheel itself, and not the more "normal" type in the clutch disk, its probably a dual mass. See if all the sprngs and plastic retainers are there. You should be able to counter-rotate the two masses against each other slightly. Measure the distance of the counter-rotation ... anything more than about 5/8" measured at the flywheel rim and it's bad. You can also run it with the cover off and check to see if both masses are running true and not wobbling. If it is bad, you can opt to replace it with a Single Mass FlyWheel and Clutch kit which is actually a lot cheaper ($500-$600) than just the stock flywheel (used to be about $1100-$1200 just for that!). The SMFW will have a lighter pedal action, you can resurface it, and its more reliable. The only drawback is some increased noise (gear rollover noise) when lugging it under decelleration and slow speeds and RPMs. Most folks are OK with that. Cheers!

1997 F250 SC 4x4, E4OD, 4.10 LS, Basically Stock, Relocated Block Heater Plug, External Trans Filter, Tru-Cool Max, I/C Mounted but not Plumbed

SOLD - 1994 F350 CC DRW 2WD PSD, 5 Speed, 4.10 LS, SBC Con-O, Baldwin Filter, Tymar HPX Hose, DPPI DP, Bilsteins, $12 AIC, Coolant Filter, Explorer Overhead Console, A-Pillar w/ISSPRO Black Ice, EV Boost, and EV Pyro, Modified Pedestal, Gutted EBPV.
Patrick Feeley is offline  
post #3 of 18 Old 10-14-2011, 04:51 PM
Compression Ignition Addict
 
catlinB's Avatar
 
Join Date: Oct 2009
Location: PEI Canada
Posts: 1,704
Thanks: 2
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
do a search for OBS chat and post your problem in there.... TONS of knowledge in there.

Catlin...

newest
2002 F-350 Lariat Ext Cab
4x4 auto, 139,000miles
with a super-chip tuner

SOLD
2000 F-250 Lariat Ext Cab
4x4 6 spd
Stock

1996
F-250 4x4 7.3L Turbo(Stock
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

5 speed ZF
3" Body Lift


Quote:
Originally Posted by JJFLASH View Post
Lol what kind of frankenstroke did you buy???

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
catlinB is offline  
post #4 of 18 Old 10-14-2011, 05:36 PM Thread Starter
Powerstroke.org Fanatic
 
jemorgan3's Avatar
 
Join Date: Aug 2010
Posts: 94
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 8 Post(s)
Feedback Score: 0 reviews
i dont think its the clutch, it only happens when its in nuetral and idling and it is on and off, one second its smooth and one second its rough as hell, then smooth again a few minutes later. the truck shifts really really well.
jemorgan3 is offline  
post #5 of 18 Old 10-15-2011, 09:17 AM
Compression Ignition Addict
 
Patrick Feeley's Avatar
 
Join Date: Oct 2011
Location: Tehachapi, CA
Posts: 2,228
Thanks: 0
Thanked 87 Times in 85 Posts
Mentioned: 0 Post(s)
Quoted: 5 Post(s)
Feedback Score: 0 reviews
Notice I really didn't mention the clutch. Trust me on this and go check yours out so at least you know what you have (DMFW or SMFW conversion) and its condition. If you do have a factory DMFW you will deal with it someday. A bad one can cause the truck to fail injection contribution tests, mimick a miss, and if ignored for too long can lead to a cracked transmission case. I've only got 29 posts on this forum, but probably over 10,000 combined on the other ones I'm on (so it's not like I haven't been around these things for a bit ). Cheers!

1997 F250 SC 4x4, E4OD, 4.10 LS, Basically Stock, Relocated Block Heater Plug, External Trans Filter, Tru-Cool Max, I/C Mounted but not Plumbed

SOLD - 1994 F350 CC DRW 2WD PSD, 5 Speed, 4.10 LS, SBC Con-O, Baldwin Filter, Tymar HPX Hose, DPPI DP, Bilsteins, $12 AIC, Coolant Filter, Explorer Overhead Console, A-Pillar w/ISSPRO Black Ice, EV Boost, and EV Pyro, Modified Pedestal, Gutted EBPV.
Patrick Feeley is offline  
post #6 of 18 Old 10-18-2011, 07:26 PM Thread Starter
Powerstroke.org Fanatic
 
jemorgan3's Avatar
 
Join Date: Aug 2010
Posts: 94
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 8 Post(s)
Feedback Score: 0 reviews
checked my clutch as you recommended and it already has a single mass clutch and it looks to be in good condition. It seems that it is a problem within the fuel system, rough stumbling idle that comes and goes when there is no load on the engine. even the smallest hint of pressing the throttle and the stumble goes away every time and the engine rev's without hesitation. never stumbles at any time other than idling. depressing the clutch, releasing the clutch, leaving it in gear or taking it out of gear has no effect on the stumble. if it is stumbling i can press and release the clutch and it does not change the stumble at all, the only thing that clears it is pressing the gas slightly. someone mentioned an IPR... what is that?
jemorgan3 is offline  
post #7 of 18 Old 10-18-2011, 07:29 PM Thread Starter
Powerstroke.org Fanatic
 
jemorgan3's Avatar
 
Join Date: Aug 2010
Posts: 94
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 8 Post(s)
Feedback Score: 0 reviews
to add one more thing,,, i bought the truck last january right before being deployed to iraq. didnt drive it before leaving, and it wasnt driven regularly until i came home last week. just this week we have replaced the fuel filter, lift pump and all the fuel lines in the engine valley chasing a fuel leak (ended up being the lift pump).
jemorgan3 is offline  
post #8 of 18 Old 10-18-2011, 07:33 PM
WNY Biodiesel Co-op
 
greasyF250's Avatar
 
Join Date: Mar 2008
Location: Orchard Park New York
Posts: 898
Thanks: 3
Thanked 2 Times in 2 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Check codes? Throttle position sensor?

2000 F250 King Ranch Crew Cab 7.3L LB 4X4 100% home brewed Biodiesel
ZF6 6SPD trans
Zoo Dad Mod
DP F5 Tuner
Wicked Wheel
AFE Intake
4" straight exhaust with 5" tip
Isspro 3 Gauge Pod
285/75/16 Cooper ATP on factory 16's
Banks Big Head
298K
greasyF250 is online now  
post #9 of 18 Old 10-18-2011, 08:11 PM Thread Starter
Powerstroke.org Fanatic
 
jemorgan3's Avatar
 
Join Date: Aug 2010
Posts: 94
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 8 Post(s)
Feedback Score: 0 reviews
No codes at all...
jemorgan3 is offline  
post #10 of 18 Old 10-18-2011, 09:08 PM
Compression Ignition Addict
 
Patrick Feeley's Avatar
 
Join Date: Oct 2011
Location: Tehachapi, CA
Posts: 2,228
Thanks: 0
Thanked 87 Times in 85 Posts
Mentioned: 0 Post(s)
Quoted: 5 Post(s)
Feedback Score: 0 reviews
The IPR is the Injection Pressure Regulator control valve (solenoid operated valve). Based on what the Injection Control Pressure (ICP) Sensor is telling the computer, the IPR is controlled to get the High Pressure Oil to be in the correct range for operation. It is located on the rear of the High Pressure Oil Pump (HPOP), which is located on the back of the HPOP Reservoir on the front top of the engine. The IPR is down towards the engine valley in front of the fuel bowl. It has a two-wire connection. Make sure that the "tin" nut that holds the IPR solenoid coil on the IPR body is snug. Also make a thorough inspection of the IPR wiring (it is part of the fuel bowl wiring harness and can get messed up due to leaking diesel fuel ... the wiring insulation turns to goo causing shorts and other issues). Cheers!

1997 F250 SC 4x4, E4OD, 4.10 LS, Basically Stock, Relocated Block Heater Plug, External Trans Filter, Tru-Cool Max, I/C Mounted but not Plumbed

SOLD - 1994 F350 CC DRW 2WD PSD, 5 Speed, 4.10 LS, SBC Con-O, Baldwin Filter, Tymar HPX Hose, DPPI DP, Bilsteins, $12 AIC, Coolant Filter, Explorer Overhead Console, A-Pillar w/ISSPRO Black Ice, EV Boost, and EV Pyro, Modified Pedestal, Gutted EBPV.
Patrick Feeley is offline  
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:
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:
OR

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
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome