99 7.3 white smoke on deceleration

Kalslade3

Registered User
Joined
Aug 31, 2021
Posts
6
Reaction score
0
Location
Michigan
I have a 99 7.3 with 175 single shots that just recently started smoking on deceleration and also when I am really getting into it. Wondering what could possibly be the issue have also a smell of raw fuel. Injectors past buzz test is there any way to test a dead or over fueling Injector? Or is there another issue that I'm over looking
 

Kevin 007

Full-floater
Joined
Mar 14, 2011
Posts
1,949
Reaction score
231
Location
Nelson BC Canada
Are you able to do a cylinder contribution test? And im assuming that is fuel smoke as you mentioned it smells of fuel, but have you confirmed that it's not engine oil consumption? And how much blow by does the engine have?
 

Kalslade3

Registered User
Joined
Aug 31, 2021
Posts
6
Reaction score
0
Location
Michigan
The smoke is blueish and can't tell on oil consumption, also blow by is little to none just smoke not actual blow by
 

Kevin 007

Full-floater
Joined
Mar 14, 2011
Posts
1,949
Reaction score
231
Location
Nelson BC Canada
If one or more cylinders were not contributing to the "contribution" that the test is testing for, it will give you a readout as to which cylinders those are, possibly indicating an injector problem, etc. and you can narrow down which cylinders to look at, which can save a great deal of time and money if the problem is in fact only with a cylinder to two.
If it's not consuming oil or coolant and we're "assuming" the engine itself is sound and not really low on compression, it's then probably related to fuel delivery, especially if the smoke stinks of fuel.
 

Kalslade3

Registered User
Joined
Aug 31, 2021
Posts
6
Reaction score
0
Location
Michigan
So after test cylinder 8 failed I got a buddy and verified the smoke coming out is blueish also notice a huge decrease in mpg, so with truck having 280k on it just got a whole new set
 

greenskeeper

Full Access Member
Joined
Mar 16, 2013
Posts
995
Reaction score
202
Location
PA
So after test cylinder 8 failed I got a buddy and verified the smoke coming out is blueish also notice a huge decrease in mpg, so with truck having 280k on it just got a whole new set
throwing parts that these engines gets expensive.

Does the truck start easily without glow plug or block heater assist? If so it would be safe to assume compression is at least ok.

Have you checked fuel pressure? Has the regulator ever been rebuilt?
 

Kalslade3

Registered User
Joined
Aug 31, 2021
Posts
6
Reaction score
0
Location
Michigan
Truck starts and runs fine no assist, idk how to check the fuel pressure on these truck nor have I really looked into it
 

greenskeeper

Full Access Member
Joined
Mar 16, 2013
Posts
995
Reaction score
202
Location
PA
Truck starts and runs fine no assist, idk how to check the fuel pressure on these truck nor have I really looked into it
99+ it's a little involved to check compared to the OBS trucks you can check with a tire gauge. if the regulator has never been rebuilt it might be worth it to rebuild as it's about $70

If the regulator has failed, you'll have little to no fuel pressure and it can run like an injector or engine problem.

 

fuurgoncin

Registered User
Joined
Jan 14, 2008
Posts
22
Reaction score
1
Location
Toronto , Ontario
Before you rip into it , try Torqueing down the Injector in question ( 10 ft-lbs)....could be just that . Acutally I would check them all once you have cover off
 

Latest posts

Forum statistics

Threads
91,217
Posts
1,128,504
Members
24,045
Latest member
Ramtough01
Top