Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

Poor perf from 7.3

Thread Tools
 
Search this Thread
 
Old Jul 11, 2005 | 08:07 AM
  #1  
enduringexplorer's Avatar
enduringexplorer
Thread Starter
|
Elder User
Joined: Sep 2001
Posts: 616
Likes: 0
From: WHITE LAKE, MI
Poor perf from 7.3

My 2003 7.3 PSD seems to have lost a little bit of power, but most importantly, it has a bog/hesitation and acts like it is "missing" for lack of a better word, from approx 2000 to 2500 rpm. At this point I can't accelerate up a hill at this rpm range. Could this be a CPS? I have the original yet, and 135,000 miles.
Thanks,
Tim
 
Reply
Old Jul 11, 2005 | 10:07 AM
  #2  
Max1775's Avatar
Max1775
Elder User
Joined: Sep 2004
Posts: 824
Likes: 0
From: Helotes, Texas
CPS is a possibility, but there are a lot of things that could cause problems like that. It wouldn't hurt to change the CPS, if it doesn't fix the problem then at least you have a spare one and have eliminated it as a possibility. It's odd that it only occurs between those RPM ranges. Have you had the codes pulled?

Max
 
Reply
Old Jul 11, 2005 | 10:13 AM
  #3  
enduringexplorer's Avatar
enduringexplorer
Thread Starter
|
Elder User
Joined: Sep 2001
Posts: 616
Likes: 0
From: WHITE LAKE, MI
No, I haven't had anyone look at it yet. I thought I would get a check engine light or something flashing? I generally don't like dealers as you need to drop the truck off for a day or two, then they rape you on the cost of repairs. I can't be without it that long. I am trying to figure this one out for myself. Could an inoperative vacuum pump have anything to do with it? My vacuum pump quit at about the same time. I haven't worried too much about it because the only thing that it seems to affect is the airflow control for the heat/ac.
 
Reply
Old Jul 11, 2005 | 10:44 AM
  #4  
Max1775's Avatar
Max1775
Elder User
Joined: Sep 2004
Posts: 824
Likes: 0
From: Helotes, Texas
You can take your truck to a auto parts store and have the codes checked. Call them first and make sure they have a scanner that will do the PSD. I don't think that a bad vacuum pump will effect the engine performance, but if you have auto hubs on your 4x4, they won't won't work correctly. I know this may sound stupid, but have you checked the air/fuel filters or replaced lately?

Max
 
Reply
Old Jul 11, 2005 | 11:37 AM
  #5  
Medic 66's Avatar
Medic 66
Posting Guru
Joined: Mar 2005
Posts: 1,460
Likes: 0
I would also ask about filter changes??
 
Reply
Old Jul 11, 2005 | 01:31 PM
  #6  
enduringexplorer's Avatar
enduringexplorer
Thread Starter
|
Elder User
Joined: Sep 2001
Posts: 616
Likes: 0
From: WHITE LAKE, MI
Yep, the fuel filter is almost new and I have the huge Napa commercial/industrial filter. At first, I started thinking it may have been a filter issue, but it runs great @ WOT. On light accel, once it hits 2000 rpm, it stutters,stumbles, kind of like when a gasser has a couple of bad plugs. once past about 2300, it smooths right out. I wasn't aware the auto parts stores could check codes, so I will give that a shot. Thanks for the tip!!
Tim
 
Reply
Old Jul 11, 2005 | 03:23 PM
  #7  
joegebff's Avatar
joegebff
Gone Fishin for Mark
Joined: Nov 2004
Posts: 1,354
Likes: 2
From: West of Houston
Club FTE Silver Member

It may be the Throttle Position Sensor......fancy talk for gas pedal.
 
Reply
Old Jul 11, 2005 | 03:33 PM
  #8  
touchofgrey's Avatar
touchofgrey
Elder User
Joined: Nov 2004
Posts: 798
Likes: 0
Originally Posted by joegebff
It may be the Throttle Position Sensor......fancy talk for gas pedal.

That would be where I'd start also. The PCM won't know it has a problem.....there won't be any codes in that situation.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

 Verdad Gallardo
story-1

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-2

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-3

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-4

Every 2026 Ford Engine Explained

 Brett Foote
story-5

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-6

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-7

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
story-8

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-9

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
Old Jul 11, 2005 | 04:50 PM
  #9  
rcain1's Avatar
rcain1
Junior User
Joined: Jul 2003
Posts: 93
Likes: 0
From: Texas
to add to your question...enduringexplorer

Can someone give me a basic list IE...
1. airfilter
2. Fuel filter

of what to change on a 7.3 tune up?

-------------------------------------------
my input:

enduringexplorer get a chip tuner if you don't already have one! It is a HUGE differance if you don't already know.
 
Reply




All times are GMT -5. The time now is 05:52 AM.

story-0
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-1
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-2
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-3
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-4
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-5
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-6
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-7
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-8
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-9
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE