2002 F550 with 7.3 runs rough when cold - Diesel Forum - TheDieselStop.com
'99 & up 7.3L Power Stroke Engine and Drivetrain Discussion of the '99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.

LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 08-07-2011, 01:51 PM Thread Starter
Junior Member
Join Date: Aug 2011
Posts: 3
Feedback Score: 0 reviews
2002 F550 with 7.3 runs rough when cold

I have a 2002 F550 with 7.3 powerstroke. A little slow to start. Runs rough when it starts and has no power until the motor warms up. No codes in computer. Truck has 135K miles.
Does anyone have any ideas?
jim otis is offline  
Sponsored Links
post #2 of 6 (permalink) Old 08-07-2011, 02:28 PM
Senior Member
tinman13kup's Avatar
Join Date: Nov 2010
Location: Ohio
Posts: 2,537
Feedback Score: 0 reviews
Do you have scanning software that can monitor engine parameters? I guess the first thing I would do is make sure the fluids and filters are good and up to date, then check the fuel pressure. You should have 50-60psi running. Are you getting any white smoke while it's cold?

99.5 PS CC 4x4 SRW ZF-6
Triple Pillar Gauges; Fuel pres, Pyro, Boost
AE, Alldatadiy, and half a clue
- AKA "The Big White Truck"
The first part to be thrown at these trucks should be a PSD compatible scanner

PM please. No Visitor Msg if you want a response anytime soon
tinman13kup is offline  
post #3 of 6 (permalink) Old 08-07-2011, 02:43 PM
Junior Member
jasons 99 powerstroke's Avatar
Join Date: Aug 2011
Posts: 11
Feedback Score: 0 reviews
i agree with tinman if have access to that (scan tool) then check out.

if not same thing happened to my buddies excursion w/ 7.3, when first started was hard to start and missed like crazy when warmed up ran like normal. ended up being the passenger side valve cover gasket had came unplugged barely enough not to let that side do its thing. like i said looked like was plugged in all the way but wasn't so maybe thats it?

check fluids though, smell oil see if diluted with fuel.

1996 F250 4x4, zf-5 trans, pure stock

99 f250 auto. triple disc convertor, 4" diamond eye turbo back straight pipe exhaust. SOLD
jasons 99 powerstroke is offline  
post #4 of 6 (permalink) Old 08-07-2011, 03:17 PM Thread Starter
Junior Member
Join Date: Aug 2011
Posts: 3
Feedback Score: 0 reviews
Yes I have SnapOn software. I have fuel pressure. I have a new fuel filter. No white smoke.
jim otis is offline  
post #5 of 6 (permalink) Old 08-07-2011, 03:33 PM
Lifetime Supporting Member
klhansen's Avatar
Join Date: Jan 2003
Location: Eagle River, Alaska
Posts: 22,194
Feedback Score: 0 reviews
Have you run a scan to see if there are any codes? That's the first step.

Also check the oil age, condition, etc. Used-up oil can cause problems with the injectors. Possibly one or more are gunked up on the oil side and won't operate correctly until the oil warms up and thins out a bit. Run an injector buzz test when cold, listening for differences in the sound of each injector (weaker than the rest), and then run one again after the engine is warmed up and running well. The weak sounding injectors will be the suspects. The buzz test activates all 8 injectors, then each one individually in numerical sequence (not firing order).

If you narrow it down, pull that valve cover, and pull the solenoids off the suspect injector and measure the clearance under the plate that the solenoid pulls up with a feeler gauge. IIRC, anything under 0.001 means the injector is worn out. While you're in there, check the under valve cover harnesses as mentioned. But at 135k miles, I'd guess your injectors should be fine if maintenance (oil changes) has been kept up and good quality fuel has been used.

Welcome to TheDieselStop

First truck -- 1929 Model A Ford pickup, restored from ground up. Wish I still had it!
99.5 F250 PSD Supercab LB 4x4, ZF-6 w/SB Con OFE, 3.73LS, Boost & pyro gauges, Swamps S175/146 injectors, DP 80 HP Econo PCM (classic version), AIS, coolant filter w/"hokum" bracket, regulated return, heated mirror mod, lighted cupholder, Marinco heater plug-in.

Hard or no-start? Check Here
klhansen is offline  
post #6 of 6 (permalink) Old 08-07-2011, 07:42 PM Thread Starter
Junior Member
Join Date: Aug 2011
Posts: 3
Feedback Score: 0 reviews
just ran an injector buzz test before motor was warmed up and found #2,#4,AND#8 were weak. Will try that. Thank you
jim otis is offline  
Sponsored Links

  Diesel Forum - TheDieselStop.com > 1999-2007 Ford Super Duties > '99 & up 7.3L Power Stroke Engine and Drivetrain
Gear in this thread - Powered by O'Reilly Auto Parts

Quick Reply

Register Now

In order to be able to post messages on the Diesel Forum - TheDieselStop.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


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.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
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