Help! Hard miss under load - Ford Powerstroke Diesel Forum
User Tag List

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 11 Old 08-05-2012, 11:15 AM Thread Starter
Powerstroke.org Rookie
 
Join Date: Aug 2012
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Help! Hard miss under load

Hello all,

I have been lurking and using all the helpful threads here since I got my truck this spring, but I have had one major unresolved issue and am about out of ideas. This is my first diesel and am not a mechanic, but consider myself mechanically inclined. Okay here is the issue:

The truck has a 1997 7.3 mated to the zf5. It idles smooth and accelerates fine in any gear to about 2500 RPM then begins to miss violently. The whole truck shudders like it is running out of fuel, but i have the FPR shimmed and fuel pressure never drops below 60psi or so at any point. If i let off the pedal i can ease it over 2500 rpm but if i put the pedal down too much it begins to shudder and stumble again. In neutral i can rev to redline with no issues.

I have replaced the IPR, CPS, checked fuel pressure and HPOP pressure at all speeds and RPM, visually inspected uppipes and turbo boots for leaks, removed cat, removed VC and checked all injector connections and unplugged each to check contribution. I have removed and inspected every sensor I can find with no luck. This is a constant problem, I have never been able to rev over 2500 under load since i've had the truck and am running out of things to check.

Thanks in advance
agamble is offline  
post #2 of 11 Old 08-05-2012, 04:01 PM Thread Starter
Powerstroke.org Rookie
 
Join Date: Aug 2012
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
bump. any ideas??
agamble is offline  
post #3 of 11 Old 08-06-2012, 09:53 AM
BANNED by Kris
 
BigFuel's Avatar
 
Join Date: Oct 2011
Location: Pasadena, CA
Posts: 6,176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Thanks: 51
Thanked 112 Times in 104 Posts
Feedback Score: 0 reviews
When this happens, what are your EGT's and boost level?

+ Matt - Star Tiger +
-Bean's: 160/100 (FF Injectors), 2/ 6-POS chips (TW & Beans tunes), Overboost controller, E-Fuel
-BANKs: downpipe, full exhaust, gauges, test pipes, intercooler
-Irate: T-4 kit, IC pipes, 3" Replacement Plenums, BASB Turbo
-Mag-Hytec trans. and pumpkin covers
-6637, CCV, IDM, 6.0 Fan, 49-Federal PCM swap, MAP line Mod
-370 Amp alt., 40k trans cooler, SRP1.1
-twin on-board air w/ 10 gal. tank

Re-pinning '97 Cali PCM to Federal
BigFuel is offline  
post #4 of 11 Old 08-06-2012, 01:34 PM Thread Starter
Powerstroke.org Rookie
 
Join Date: Aug 2012
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
I dont have a gauge for egt yet because i dont have a tune. and i dont have a boost gauge either but that will probably the next area i investigate. However if it were low boost wouldn't i be getting thick black smoke?
agamble is offline  
post #5 of 11 Old 08-08-2012, 07:14 PM Thread Starter
Powerstroke.org Rookie
 
Join Date: Aug 2012
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
bump. anyone have any thoughts???
agamble is offline  
post #6 of 11 Old 08-09-2012, 10:01 AM
BANNED by Kris
 
BigFuel's Avatar
 
Join Date: Oct 2011
Location: Pasadena, CA
Posts: 6,176
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
Thanks: 51
Thanked 112 Times in 104 Posts
Feedback Score: 0 reviews
When it's shuddering is it always in the same gear or does it not matter the gear only the RPMs?

+ Matt - Star Tiger +
-Bean's: 160/100 (FF Injectors), 2/ 6-POS chips (TW & Beans tunes), Overboost controller, E-Fuel
-BANKs: downpipe, full exhaust, gauges, test pipes, intercooler
-Irate: T-4 kit, IC pipes, 3" Replacement Plenums, BASB Turbo
-Mag-Hytec trans. and pumpkin covers
-6637, CCV, IDM, 6.0 Fan, 49-Federal PCM swap, MAP line Mod
-370 Amp alt., 40k trans cooler, SRP1.1
-twin on-board air w/ 10 gal. tank

Re-pinning '97 Cali PCM to Federal
BigFuel is offline  
post #7 of 11 Old 08-09-2012, 01:16 PM Thread Starter
Powerstroke.org Rookie
 
Join Date: Aug 2012
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
i can get to redline in granny gear and like 2700 rpm in second but third fourth and fifth i can only get to 2500 when accelerating without bucking
agamble is offline  
post #8 of 11 Old 08-17-2012, 05:43 PM
Powerstroke.org Fanatic
 
injection direction's Avatar
 
Join Date: Nov 2009
Posts: 101
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
bump bump bump

Injection Direction

1999 (early, 10/98) F250 XL CC/LB 4WD 4R100, str8 pipe, CCV mod, bypass trans filter, 3.73, DIY napa air filter, 261k

1995 E350 XLT str8 pipe, SS (super stocker), 321k

No replacement for displacement
injection direction is offline  
post #9 of 11 Old 05-18-2013, 06:44 PM
Member
 
psdstrkD95's Avatar
 
Join Date: Jan 2013
Location: Anchorage Alaska
Posts: 65
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Just mechanically inclined as well. Could it be a balance issue somewhere that load/rpm based the higher the gear the higher the engine load at any rpm so maybe the dampers bad? just a guess to keep everyone brain storming

I couldnt have said it better myself.
psdstrkD95 is offline  
post #10 of 11 Old 05-18-2013, 07:47 PM
Premium Member
 
nohsp4u's Avatar
 
Join Date: Mar 2013
Location: Foresthill CA
Posts: 261
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Quote:
Originally Posted by agamble View Post
Hello all,

I have been lurking and using all the helpful threads here since I got my truck this spring, but I have had one major unresolved issue and am about out of ideas. This is my first diesel and am not a mechanic, but consider myself mechanically inclined. Okay here is the issue:

The truck has a 1997 7.3 mated to the zf5. It idles smooth and accelerates fine in any gear to about 2500 RPM then begins to miss violently. The whole truck shudders like it is running out of fuel, but i have the FPR shimmed and fuel pressure never drops below 60psi or so at any point. If i let off the pedal i can ease it over 2500 rpm but if i put the pedal down too much it begins to shudder and stumble again. In neutral i can rev to redline with no issues.

I have replaced the IPR, CPS, checked fuel pressure and HPOP pressure at all speeds and RPM, visually inspected uppipes and turbo boots for leaks, removed cat, removed VC and checked all injector connections and unplugged each to check contribution. I have removed and inspected every sensor I can find with no luck. This is a constant problem, I have never been able to rev over 2500 under load since i've had the truck and am running out of things to check.

Thanks in advance
Is your CEL on? if so, scan and get code, that would help a lot. If you have access to a scanner you can use while driving, even better.

1997 F-350 XLT Lariat Crewcab long box 4x4. Oxford white with an ugly green. 133xxx miles. Hide away goose neck, banks turbo, exhaust, inner cooler, intake filter and gauges.

nohsp4u is offline  
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