How long would you run these injectors?

Bdsankey

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If it's hazing as bad as you say I don't think the cleaner is going to be your saving grace. Mine was in the same boat (I think the kid ran cleaner through it then parked it to be sold) and running injector cleaner got me maybe 600 more miles when I had to do it. Your result may vary but it sounds like it's time to start saving.
 

fl0w3n

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If it's hazing as bad as you say I don't think the cleaner is going to be your saving grace. Mine was in the same boat (I think the kid ran cleaner through it then parked it to be sold) and running injector cleaner got me maybe 600 more miles when I had to do it. Your result may vary but it sounds like it's time to start saving.

Yeah maybe I got fooled and the guy ran some cleaner through, but I’d be surprised. The timing is pretty coincidental though.

It isn’t necessarily the money, I bought it knowing I would be putting injectors in, it’s the time. I don’t move into our new house and get my garage setup until july 18th/19th so I’m probably not starting injectors until that following weekend.
if the cleaner can get me another month of safe use out of the truck then I’ll be happy.
 

Bdsankey

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Yeah maybe I got fooled and the guy ran some cleaner through, but I’d be surprised. The timing is pretty coincidental though.

It isn’t necessarily the money, I bought it knowing I would be putting injectors in, it’s the time. I don’t move into our new house and get my garage setup until july 18th/19th so I’m probably not starting injectors until that following weekend.
if the cleaner can get me another month of safe use out of the truck then I’ll be happy.

Honestly there’s one way to find out. If it starts smoking/hazing bad park it before you wash down a cyl wall.
 

fl0w3n

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It only smoked heavy a couple times and then it’s gone away. More times than not it’s a very light haze or nothing. Seems like an injector is occasionally sticking.

I got The cleaner in finally and ran it through today. Here’s some results. Nothing stellar but looks like it helped a little. The fuel in the jug looked a little dark, so I’ll probably run it another time or two.


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fl0w3n

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It hasn’t really hazed as much since the cleaning, and I don’t think it has since I changed from a Napa fuel filter to a GM filter 600 miles ago, but it does occasionally idle with a faint black smoke and smell like burned fuel (not sweet)

occasionally it does sound like it fuel knocks once or twice during cranking, or does a funny quick skip.

I’m contemplating robbing my 02 of the SAC45s and all the parts I just put in and have driven twice...which seems dumb, but on the other hand it sounds better than dropping the money right now haha

I’m going to try running at least one more cleaning through it, but I’ll probably feed the return into an empty jug. It looked pretty dirty last time and I think I can help the filter and injectors out by not pushing it back through
 

DAVe3283

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If it is holding pretty steady, I'd keep running it. Maybe go ahead and clean it one more time, but no need to do all the labor to swap injectors yet. Just save up, and it may well keep kicking long enough.

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fl0w3n

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That’s what I’m hoping for. Although it is pulling more out of the main rate now, I was seeing it bounce between 4-5 today. Balance rate is staying relatively the same it looks like.

once I get settled into the new house in the next couple weeks, I plan on pulling an oil sample to send to Blackstone, and maybe pulling a glow plug on #8 and sticking a scope down there - would I be able to see any signs of cylinder wall damage? Or if I do see signs, is it too late already?
 

fl0w3n

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Oh, I also have a random question- what is happening around 2500 rpm that causes a drastic change in audio tone? The characteristic clack of the diesel goes away and is replaced by a more consistent hum.
I’m guessing some sort of change to fuel or timing?
Just curious.
 

Bdsankey

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Oh, I also have a random question- what is happening around 2500 rpm that causes a drastic change in audio tone? The characteristic clack of the diesel goes away and is replaced by a more consistent hum.
I’m guessing some sort of change to fuel or timing?
Just curious.

Depending on your tune I’m betting it’s pilot injection turning off.


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2004LB7

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That’s what I’m hoping for. Although it is pulling more out of the main rate now, I was seeing it bounce between 4-5 today. Balance rate is staying relatively the same it looks like.

once I get settled into the new house in the next couple weeks, I plan on pulling an oil sample to send to Blackstone, and maybe pulling a glow plug on #8 and sticking a scope down there - would I be able to see any signs of cylinder wall damage? Or if I do see signs, is it too late already?

your going to need a mighty small boroscope to fit the glow plug hole. I'm talking like 1/8" or smaller.

the easiest route is through the injector hole. I'd wait for the oil sample report before worrying about it

since the main rate is dropping but the balance is staying the same likely means they are all leaking a little bit more then before. watch for smoke and knocking especially on start up
 

fl0w3n

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your going to need a mighty small boroscope to fit the glow plug hole. I'm talking like 1/8" or smaller.

the easiest route is through the injector hole. I'd wait for the oil sample report before worrying about it

since the main rate is dropping but the balance is staying the same likely means they are all leaking a little bit more then before. watch for smoke and knocking especially on start up
It’s knocking on startup already, or at least just once or twice during the quick crank cycle
 

2004LB7

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my guess is that the injectors are probably leaking down into the piston bowl and causing knocking on startup.

try running a quart of ATF in the tank and see if it changes any
 

fl0w3n

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my guess is that the injectors are probably leaking down into the piston bowl and causing knocking on startup.

try running a quart of ATF in the tank and see if it changes any
Does any brand of ATF matter lol
Depending on your tune I’m betting it’s pilot injection turning off.


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The noise you are hearing is pilot injection turning off most likely.
Weird, I thought it was something like that... but I thought pilot injections main purpose was for making it sound quieter? But it actually sounds smoother and quieter with it off around 2500 RPM
 

fl0w3n

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Not worth starting a new thread for this, I'm trying to confirm the noise I'm hearing from the steering column. All my GMT800's have had a slight clunk to some degree when turning, and the 04 does it but it also rattles at idle and it's getting damn annoying. If I turn the wheel just a little so that there's pressure on it, it goes away.

I believe it's that green bearing that's interior on the column, but I just want to confirm - part #
88963617
 

2004LB7

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Does any brand of ATF matter lol


Weird, I thought it was something like that... but I thought pilot injections main purpose was for making it sound quieter? But it actually sounds smoother and quieter with it off around 2500 RPM

I use the cheapest ATF I can find

pilot does as you say but can be less affective at higher RPMs. turning off polit also has the net result of effectively reducing timing
 

fl0w3n

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I use the cheapest ATF I can find

pilot does as you say but can be less affective at higher RPMs. turning off polit also has the net result of effectively reducing timing
With a full tank I assume?
 

Chevy1925

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ATF killed my injectors in my LB7 before i went to LLY. i would not recommend doing it. If the GM cleaner had already gone through, thats going to work the best. It does not lubricate and eats up the parts. i ran 1 quart per full tank over 3 tanks, i had done the gm cleaner in the truck maybe 3-4 tanks prior. never noticed a difference with the atf other than the injectors got louder quickly.
 

fl0w3n

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I plan on definitely running GM cleaner at least one more time, I still have 4.5 bottles of it. I’ll probably run the supply and return into two separate containers this time... it looked a dirty last time, but I suppose it looking dirty is a good thing?

I just grabbed all my tools and garage stuff from SoCal to move into my new house, once I get the trailer out of the driveway blocking my garage I’ll mess with the truck.0ABDA90E-69AA-4DB3-8D80-37815F80D726.jpeg