Major LB7 problems -- need help

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
Hello everyone. Been reading on here for years and decided it's time to join. I hope everyone here is doing well, and keeping some type of sanity. I certainly have spent an enormous amount of time recently trying to ressurect my daily driver, at the worst of times. As a newbie here I don't even know where to start. Hoping somebody can guide me to find what I seek.

Having trouble with my LB7 and am already half the trucks cost deep in parts. Low boost. Had massive holde in the intercooler. Replaced intercooler still no boost. Pressurized charge system held 20psi for 30 seconds no leaks. Rebuilt turbo with cartridge. New turbo gaskets. Still no boost. Lots of black smoke above 1500 rpm. Getting about 10 psi boost max. Have ordered exhaust manifolds and gaskets but I'm nervous to attempt those exhaust bolts. Also brand new MAF sensor yesterday didn't help anything. New fuel filter and air filter. Pulling my hair out. Am on the right track or missing something?

Thanks.
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
No codes. I have a sporadic tranny code when getting range shift inhibited but I forget what the number was. Usually goes away on its own
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
Tomorrow I will borrow a scanner and post my live data. This truck has never given me a code even when my injectors were leaking and I was pluming white smoke. I fixed that 2 years ago. I had a massive hole in my IC I assume was from a rock. Thinking I drove like that for months
That's why I went ahead rebuilding the turbo. I did however reuse the manifold to up pipe gaskets. So at this point not sure if I should swap the gaskets out or do the whole manifold replacement. Parts are paid for but I do not have torches or anything crazy. Doing this in a field basically
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
Last time I logged data before the turbo rebuild I saw the desired and actual pressure were very close. The smoke clouds are thick black. Could swear its an expensive smoke tune. No power though
 

gmduramax

Shits broke
Jun 12, 2008
3,619
9
38
Nor cal
Your injectors could be bad again, your CP3 could be weak. Wastegate could be broken or malfunctioning. If it was your exhaust gaskets you would hear a screeching sound under acceleration unless your exhaust leak is huge.
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
I had the turbo apart and cleaned it up pretty good. Waste gate is all intact and seats nice. Actuator is strong and opens around 30 psi. I do hear a louder tick from passenger side at idle. Not sure if exhaust leak or fuel knock. Not exactly a seasoned mechanic :)
 

blk smoke lb7

<-----Lots of green $
Nov 8, 2010
5,693
0
36
53
belvidere,ill
You had the turbo rebuilt or you took it apart and cleaned it? I'm wondering if the turbo is hitting the housing and dragging possibly.Just a thought.
 

blk smoke lb7

<-----Lots of green $
Nov 8, 2010
5,693
0
36
53
belvidere,ill
Also where did you get your injectors from? Did the problem kind of start around that time?I've seen people buy old injectors run them thru a cleaner and resell them as refurbished.
 

ZeroGravity58

Active member
Mar 23, 2008
1,123
2
38
34
Maryland
If you air tested the intercooler and piping and it held and you have plenty of fuel if it is smoking black, only leads me to think it's the turbo/wastegate. If you had a up pipe or manifold leaking that bad it should be easy to see as you will have smoke rolling out from under the hood.
 

Dirtymaxx03

Active member
Aug 3, 2009
3,103
0
36
check your intercooler piping. i was having boost issues on my lb7 and found a big hole in the intercooler piping from it rubbing on a metal line. i think it was on the drivers side.
 

KyleC4

Tech
Dec 30, 2016
334
6
18
Bay Area
Definitely borrow that scanner and look at data and all DTC’s if any. Look at all things mentioned like rail pressure desired vs actual. Look at MAF sensor reading and report back with numbers.....also look at your MAP sensor and see what it’s saying as well.
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
You had the turbo rebuilt or you took it apart and cleaned it? I'm wondering if the turbo is hitting the housing and dragging possibly.Just a thought.
I replaced the entire rotating assembly brand new. Cleaned up the housings with some light soda blasting and brake clean. Didn't see any cracks or obvious signs of damage.
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
Also where did you get your injectors from? Did the problem kind of start around that time?I've seen people buy old injectors run them thru a cleaner and resell them as refurbished.
I got the injectors from injectorsdirect.com... not sure how reputable they are but I didn't have any problems with them. That was a few years ago and I did the swap myself. Those were the white smoke days. And believe me, they were bad days. Now I'm in the black smoke. Started around October while I was hauling a trailer through some hills. Just started puffing little spurts of black... Nothing too dramatic. Still had tons of power and I didn't think much of it. Progressively got worse. Now I won't even drive it aside from a quick test drive.
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
check your intercooler piping. i was having boost issues on my lb7 and found a big hole in the intercooler piping from it rubbing on a metal line. i think it was on the drivers side.
I've checked this at every step. Pressurizing from the turbo inlet at 40 psi. No leaks. Aside from the motor starting to turn over from the leak down it holds. I wish it was this infamous hole everyone gets. My piping is well spaced from lines as I've replaced the steering lines and moved them a bit.
 

Citidiot90

Person
Apr 22, 2020
24
0
0
Canada
Okay so i logged some data. first one is at idle. second is in park at half throttle. third one is in drive with brakes applied and half throttle
https://drive.google.com/open?id=1UR5DQlJz8Bz2IWuhtKXlQ7GXmlUZr7XA
https://drive.google.com/open?id=1nEjHZH1drYejE01gUj7Uwq6mczUiYshw
https://drive.google.com/open?id=1_nxVq1nWQvZufyHy1iqNDFTJvdGGIQHR

Edit: here are the stored DTCs:
P0700 Transmission Control Module Requested MIL Illumination
P0733 incorrect 3rd gear ratio
C0035 Left front wheel speed sensor circuit malfunction
C0040 Right front wheel speed sensor circuit malfunction
C0201 Open or shorted master cylinder pressure sensor
B0090 Left Frontal restraints sensor
U1000 Class 2 data link malfunction
 
Last edited:

Users Who Are Viewing This Thread (Users: 0, Guests: 1)