Need some technical advice...

[Goad]

Soooo here I am again (previous thread) ....I got that motor sent back and got my money back from them without issue.

I picked up another motor locally from a friend of a friend. The story on it is the guy bought the truck at an auction. It was a grandpa truck - totally unmolested and well taken care of. He threw a bunch of mods at it all at once and it ran like shit. He put all new injectors in it, then it still ran like shit. He was over it and frustrated so he got a junk yard motor and it STILL ran like shit...So he took the tuner off it, and it fixed all the issues. Turned out he had a short in the harness for the live tuner he put in. Replaced that and now the truck runs good.

So in theory the motor he pulled out has new injectors and never had an issue to begin with - right? Boy I was wrong....

The truth is he actually bought the injectors off ebay.....and went through 2 sets (returned the first set) before he got ones that worked. He claims it did not smoke when he pulled the motor.

So here I am again, many months later and still don't have a running truck. After I threw that motor in and fired it up only to have it blow super thick grey smoke, you can fully appreciate my extreme frustration. The truck has been sitting for months and I gave up on it.

Here's my questions...I will do my best to line things out to avoid confusion...

I know the quick knee jerk response is to yell "replace the injectors"......but before a drop a few grand more on this truck, I want to make sure I am not overlooking anything.

The truck immediately chucks out thick grey smokes upon firing it up. Idle is super lopey and rough. (link to audio/video below)

I cannot run a decent balance rate test. I was told if it's run for that long, I run the risk of doing serious damage.

Is there any programming between ECU / FICM / Injectors? I tried running the FICM original to the truck and I got the worst results. I ran the FICM original to the replacement motor and it still smoked, but not as bad.

Other than injectors, what else could cause this that I should check?

Attached is a picture of the smoke for reference in case you guys arent able to view the videos

Here is a link to a folder that shows the idle and another video that shows a screen recording of the Torque App balance rate test, which I am not sure if it's useful at all, but included it anyways. https://drive.google.com/drive/folders/16NXMh_PJ8MqTswOOeMNUjuYnBSPlfKhe?usp=sharing

I am leaning towards replacing the injectors, but before I drop the money on it, I just want to be sure I am not missing something else.

 

[Goad]

One other thing I would like to note is I also tried swapping the fuel pressure regulator between the new/old motors - no change.

 

[Bdsankey]

Have you done a compression test? Leak down test? Is everything plugged in properly?

 

[Dozerboy]

How old is the fuel your running through it?

you could always send the injectors off to be tested before replacing them.

 

[Goad]

Have you done a compression test? Leak down test? Is everything plugged in properly?

I triple checked all connections - no check engine codes being reported either.

I did not do a compression or leak down test.

 

[Goad]

How old is the fuel your running through it?

you could always send the injectors off to be tested before replacing them.

The fuel was maybe 6-8 months old at the time. The previous motor had a blown head gasket and in the process it melted the head and put aluminum down in the cylinder. I tried just replacing the head gasket, but it still had low compression in that cylinder.

 

[Dozerboy]

Might try some fresh fuel, but I’d be surprised if that was it. Compression and leak down test are wise. You running stock tuning? Are the injectors supposed to be stock? So data logs that show timing, Injector open time, and fuel rail pressure would be helpful.

 

[Chevy1925]

whens the last time you changed the oil in that engine? be careful you dont overly contaminate it with fuel starting it and running it in its current condition.

IMHO, id either send the injectors out to a reputable shop for testing or just buy new ones. compression and leak down are not a bad idea by any means but all signs are pointing to injectors from what i see.

does the smoke smell sweet or like raw fuel and burn your eyes? might be a pulled injector cup but i have my doubts.

 

[fl0w3n]

I noticed in your video there's no MAF sensor, not sure that could cause that significant of an issue?

 

[Dukchunter]

Stop throwing money at it and do some diagnostic work. Compression test should be first before anything else. Harbot freight has a decent compression test kit for cheap if you don't have one.
Identify the cause of smoke... oil, fuel, coolant?

The volume of smoke would concern me. I would not run the truck at all unless absolutely necessary to troubleshoot.

Massive amounts of grayish smoke leads me to believe it is a fueling issue but not necessarily an injector issue

Sent from my SM-G960U using Tapatalk

 

[Chevy1925]

I noticed in your video there's no MAF sensor, not sure that could cause that significant of an issue?

its at the top of the intake tube

 

[Mike L.]

Almost sounds like it has gas in it.

 

[Bdsankey]

Almost sounds like it has gas in it.

Couldn't resist that one.

 

[Goad]

If I were to fill a gas can with diesel and hook up a fuel line to draw from it....where should I have that hose go to? The inlet of the fuel filter head?

Also, should I fill the fuel filter with anything to help clean the injectors? or is all that stuff snake oil?

 

[2004LB7]

On the back side of the engine, driver side. There are two fuel lines. A supply and return. Disconnect each line and put them into a clean bucket with your fuel and cleaner. You may need to extend them with additional hoses.

 

[Goad]

What cleaner do you recommend?

 

[2004LB7]

See this thread

GM injector cleaner results

So my balance rates haven't been the greatest for a little while now. Mainly #5 injector. So I figured I would do a DIY injector cleaning with the gm injector cleaner. So I searched for the DIY thread and followed it. Pretty simple.... I will compare balance rates before and after, I'm...

www.duramaxdiesels.com

 

[Goad]

So that ACDELCO x66P stuff is not readily available.....seems like everywhere is sold out of it...and the only stuff available is on ebay for $75 a bottle.

Anyone tried running that Hot Shot cleaner through the system like in that article above? If so, what mixture do you recommend?

 

[2004LB7]

I would do a whole bottle of cleaner in a gallon jug and the rest diesel for the above cleaning procedure. Then put a bottle in the tank

 

[Goad]

Based on the video shown, do you think its wise to run this motor at any length of time with that hot shot injector cleaner stuff? I got some delivered, just curious if I am going to do more damage than its worth trying to band-aid the issue