Notices
Modular V10 (6.8l)  

PLEASE HELP!!

Thread Tools
 
Search this Thread
 
Old Sep 4, 2025 | 08:33 PM
  #1  
Bklawn82's Avatar
Bklawn82
Thread Starter
|
1st Gear
Joined: Sep 2025
Posts: 1
Likes: 1
From: Charleston, SC
PLEASE HELP!!

Hi everyone! Great to be here. I've got a strange issue that has gone on for a while now..Just to give a background on the truck: 1999 F250 SuperDuty v10 6.8L. Bought it a month ago and steadily has gotten worse. Started with just a shake or shudder at 40-45. Went ahead and changed all fluids, spark plugs, COP, MAF sensor, IAT sensor and some fuses. No CATS. So, now to the current condition.. It starts up no problem. Idles ok then starts like coughing out the exhaust. When you put in gear and hit the gas it just creeps along with more of the coughing/back fire type sound. Gets up to about 40 and shakes violently. It will go over 40 mph but takes a year and then shakes more. Also if you step on the gas it shakes no matter what speed. I've checked the codes and there's nothing related to the pcm. No misfires with live data. Im stumped! Please help!! Need to resolve this ASAP as its a work truck. TIA
 
Reply
Old Sep 5, 2025 | 06:17 PM
  #2  
charlie g's Avatar
charlie g
FTE Community Team
Joined: Dec 2023
Posts: 8,849
Likes: 4,266
From: sussex county, nj
Club FTE Gold Member
welcome to

start by doing the cheapest, a compression and leak down test
 
Reply
Old Sep 5, 2025 | 09:12 PM
  #3  
ashleyroachclip's Avatar
ashleyroachclip
Laughing Gas
15 Year Member
Liked
Loved
Community Favorite
Joined: Oct 2007
Posts: 963
Likes: 105
Sounds that you have a scanner , will it do live data ?
if so , what are tour shot term and long term fuel trims ?
what is the maf readings .
these are OBD1 , so they are not going to give you clear and accurate cylinder misfire, just general multiple cylinder misfire...
 
Reply
Old Sep 6, 2025 | 08:48 AM
  #4  
charlie g's Avatar
charlie g
FTE Community Team
Joined: Dec 2023
Posts: 8,849
Likes: 4,266
From: sussex county, nj
Club FTE Gold Member
1999 is OBD 2
 
Reply
Old Sep 6, 2025 | 12:01 PM
  #5  
CathedralCub's Avatar
CathedralCub
FTE Community Team
5 Year Member
Community Builder
Community Influencer
Community Favorite
Joined: Jan 2019
Posts: 10,768
Likes: 1,506
Club FTE Gold Member
Does it have an aftermarket program in it to delete the catalytic converter from its mind? . . . and probably give more power/economy/etc.?

Are there any other major modifications with it?

How clean is the air filter?
 
Reply
Old Sep 8, 2025 | 11:30 AM
  #6  
ashleyroachclip's Avatar
ashleyroachclip
Laughing Gas
15 Year Member
Liked
Loved
Community Favorite
Joined: Oct 2007
Posts: 963
Likes: 105
Originally Posted by charlie g
1999 is OBD 2
it is actually OBD 1 , I have the same model year . I believe 2000 was full OBD2 Compliant .
 
Reply
Old Sep 8, 2025 | 11:35 AM
  #7  
ashleyroachclip's Avatar
ashleyroachclip
Laughing Gas
15 Year Member
Liked
Loved
Community Favorite
Joined: Oct 2007
Posts: 963
Likes: 105
Sounds like a fuel issue.
can you check fuel preasure from the Schrader valve on the passenger side .
if you don't have a dedicated test tool , you can use a tire pressure gauge .
 
Reply
Old Sep 10, 2025 | 04:38 PM
  #8  
charlie g's Avatar
charlie g
FTE Community Team
Joined: Dec 2023
Posts: 8,849
Likes: 4,266
From: sussex county, nj
Club FTE Gold Member
Originally Posted by ashleyroachclip
it is actually OBD 1 , I have the same model year . I believe 2000 was full OBD2 Compliant .
very odd since in 1996 obd 2 rules came into affect the 95 150 i had , had it
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-1

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-2

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-3

Every 2026 Ford Engine Explained

 Brett Foote
story-4

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-5

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-6

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

 Verdad Gallardo
story-7

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

 Joe Kucinski
story-8

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

 Brett Foote
story-9

Top 10 Ford Truck Tragedies

 Joe Kucinski
Old Sep 10, 2025 | 11:43 PM
  #9  
CathedralCub's Avatar
CathedralCub
FTE Community Team
5 Year Member
Community Builder
Community Influencer
Community Favorite
Joined: Jan 2019
Posts: 10,768
Likes: 1,506
Club FTE Gold Member
Originally Posted by Bklawn82
1999 F250 SuperDuty v10 6.8L
Originally Posted by ashleyroachclip
these are OBD1
Originally Posted by charlie g
1999 is OBD 2
Originally Posted by ashleyroachclip
it is actually OBD 1
Originally Posted by charlie g
very odd since in 1996 obd 2 rules came into affect
I have a 1999 F-350 and 1999 F-53 in my yard right now that both have V-10s and both are ODB2.

@ashleyroachclip, are you talking gas or diesel?
 
Reply
Old Sep 11, 2025 | 06:03 AM
  #10  
charlie g's Avatar
charlie g
FTE Community Team
Joined: Dec 2023
Posts: 8,849
Likes: 4,266
From: sussex county, nj
Club FTE Gold Member
Originally Posted by ashleyroachclip
if you don't have a dedicated test tool , you can use a tire pressure gauge .
WHAT?? thats a fire waiting to happen , most auto parts stores rent the kit, play safe do it right or don't do it.


 
Reply
Old Sep 11, 2025 | 10:23 PM
  #11  
CathedralCub's Avatar
CathedralCub
FTE Community Team
5 Year Member
Community Builder
Community Influencer
Community Favorite
Joined: Jan 2019
Posts: 10,768
Likes: 1,506
Club FTE Gold Member
I agree!
 
Reply
Old Sep 12, 2025 | 08:44 AM
  #12  
ashleyroachclip's Avatar
ashleyroachclip
Laughing Gas
15 Year Member
Liked
Loved
Community Favorite
Joined: Oct 2007
Posts: 963
Likes: 105
Originally Posted by CathedralCub
I have a 1999 F-350 and 1999 F-53 in my yard right now that both have V-10s and both are ODB2.

@ashleyroachclip, are you talking gas or diesel?
mine is a V10 gasser , not aware of a V10 diesel...lol
when you look closer , you will see these until 2000 , we're called OBD 2 , BUT you will see there is very limited functions .
can not read individual cylinder misfire, fuel pressure , etc.
most scanners , when you scroll through the settings , you will see they are in fact OBD1.
 
Reply
Old Sep 12, 2025 | 10:25 AM
  #13  
charlie g's Avatar
charlie g
FTE Community Team
Joined: Dec 2023
Posts: 8,849
Likes: 4,266
From: sussex county, nj
Club FTE Gold Member
there was a v10 diesel way back. just it wasn't a ford, it was a VW in the Touareg 5.0l twin turbo v10, lots of fun to work on, NOT!
 
Reply
Old Sep 12, 2025 | 11:50 PM
  #14  
CathedralCub's Avatar
CathedralCub
FTE Community Team
5 Year Member
Community Builder
Community Influencer
Community Favorite
Joined: Jan 2019
Posts: 10,768
Likes: 1,506
Club FTE Gold Member
Originally Posted by CathedralCub
I have a 1999 F-350 and 1999 F-53 in my yard right now that both have V-10s and both are ODB2.

@ashleyroachclip, are you talking gas or diesel?
Originally Posted by ashleyroachclip
mine is a V10 gasser , not aware of a V10 diesel...lol
Yup, me either. At the time, all I knew of yours was this:

Originally Posted by ashleyroachclip
it is actually OBD 1 , I have the same model year . I believe 2000 was full OBD2 Compliant .
. . . and your profile doesn't mention the engine, so I asked.

Originally Posted by ashleyroachclip
when you look closer , you will see these until 2000 , we're called OBD 2 , BUT you will see there is very limited functions .
can not read individual cylinder misfire, fuel pressure , etc.
most scanners , when you scroll through the settings , you will see they are in fact OBD1.
I'll submit that these are OBD2, with limited functionality, but are not OBD1. They have a lot of basic OBD2 functionality, OBD2 P-codes, and there are OBD2-based programmers and tuners for them, but yes are more limited than just a model year or two later. An OBD2 reader isn't able to talk OBD1 to anything, and an OBD1 reader won't talk with these. If there any 1999 F-250's or F-350's out there that don't have a OBD2 port and PCM on them from the factory, I'm not aware of them but I'm open to the possibility. The reason I'm clarifying this is that we can still do some OBD2 diagnostics here, albeit without some of the more advanced features.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bdent11
Modular V8 (4.6L, 5.4L)
5
Jun 19, 2016 09:18 PM
Myfirstnewtruck
1997 - 2003 F150
3
Nov 11, 2004 05:44 PM
jbblevin1
1983 - 2012 Ranger & B-Series
8
May 17, 2002 04:36 PM
jbblevin1
1983 - 2012 Ranger & B-Series
1
May 9, 2002 08:20 AM




All times are GMT -5. The time now is 05:06 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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
story-9
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE