01 LB7 Duramax

[OutlawRider]

So these are brand new injectors with maybe 500-1000 miles on them. Still getting fuel in the crankcase. Putting new lines and banjo bolts in and didn’t expect this.

Why am I getting this carbon buildup so fast? Is it oil getting around the rings? Is it running rich? All of the balance rates were looking good (right at 0 except for #7 which was 2.5. But these are brand new Bosch injectors (from LDS).

 

[OutlawRider]

Bump.. any thoughts or is this normal?

 

[Elvis-n-texas]

Are these the new style injector tip?
I have an 03, and installed LDS new style and a EFI 5dsp tune 4 years ago, and have had zero issues.

I replaced all lines, cups, seals and injectors at one time. Upgraded to the later FPR, all new soft lines, new filter head and a lift pump with a generic WIX CAT filter.

 

[OutlawRider]

I would assume so. It runs fine, just had a leak somewhere and had to tear into it again. I replaced all the hard lines and banjo bolts, new gaskets, I placed a lift pump and has a new CP3 that I placed prior to injectors.

I just was surprised to see that much carbon buildup. The computer is reading 40lbs of boost which I know is incorrect so I am replacing both boost (MAP) and atmospheric pressure sensors.

 

[Elvis-n-texas]

The early ECU cant read/understand boots above 25 psi, if I remember correctly.

I cant speculate on carbon buildup, I would mail images to LDS...

The LB7 is a great powerplant. I love mine, just wish it had 10 speeds ;)
Best of luck..

 

[OutlawRider]

The early ECU cant read/understand boots above 25 psi, if I remember correctly.

I cant speculate on carbon buildup, I would mail images to LDS...

The LB7 is a great powerplant. I love mine, just wish it had 10 speeds ;)
Best of luck..

That’s why I assumed the sensors had issues. It may even just be a wiring problem. I’m more worried about the fuel in oil issue and then go from there. Emailing those images to LDS isn’t a bad idea either though.

 

[Gdogg]

Who is LDS?
I think a lot of the "Bosch" stuff for sale on line.... especially ebay is counterfeit Bosch. I do a lot of diesel work, I did it for a living and I've done it 40 years now. I have had people bring me trucks that somebody else put injectors in and after that it still doesn't run right and the problem is they were not OEM quality parts. I actually had a LB7 here right that somebody did the fuel system (9k worth of work) and after a couple of months it only male 250 psi rail pressure.
You either have a return line leaking or injector leaking causing the fuel in the oil, that's why GM changed the design with the LLY and got all that stuff outside the engine, I have a buddy the spent 10 years on the Duramax program at GM and he was in the dyno room, he use to tell me they had engines "run away" on the dyno because the oil would become saturated with fuel, it would get past the rings on run on it. He said when that happened they just stood back and let them blow up.

Did you use all new washers on the return lines? are all the washers in? and you didn't miss one?
I think my buddy said they would run those engines without the valve covers so they could find the leak, and that would be a lot of work to do with the engine in a truck.
I think those injectors can leak fuel them self's.

 

[OutlawRider]

Who is LDS?
I think a lot of the "Bosch" stuff for sale on line.... especially ebay is counterfeit Bosch. I do a lot of diesel work, I did it for a living and I've done it 40 years now. I have had people bring me trucks that somebody else put injectors in and after that it still doesn't run right and the problem is they were not OEM quality parts. I actually had a LB7 here right that somebody did the fuel system (9k worth of work) and after a couple of months it only male 250 psi rail pressure.
You either have a return line leaking or injector leaking causing the fuel in the oil, that's why GM changed the design with the LLY and got all that stuff outside the engine, I have a buddy the spent 10 years on the Duramax program at GM and he was in the dyno room, he use to tell me they had engines "run away" on the dyno because the oil would become saturated with fuel, it would get past the rings on run on it. He said when that happened they just stood back and let them blow up.

Did you use all new washers on the return lines? are all the washers in? and you didn't miss one?
I think my buddy said they would run those engines without the valve covers so they could find the leak, and that would be a lot of work to do with the engine in a truck.
I think those injectors can leak fuel them self's.

LDS is Lincoln Diesel Specialties.

Can’t prove it, but they were bought as Brand New, not reman, Bosch injectors. Two thing the first time I did it that I am correcting this time is yes, brand new return lines and cleaning the cups better. I bought brand new copper washers and seals for all brand new bolts on the return lines. It had brand new HP lines when I first put new injectors in 1000 miles ago so I am not putting new ones of those in it. It actually didn’t need I hectors when I redid it the first time. It ran just fine, just lots of fuel in the oil (bought it this way). But I decided to put new everything in but apparently not enough. I even ran it with the valve covers off but found no obvious leaks.

I was just curious if that amount of carbon buildup in 1000 miles on the tips was normal.

 

[Gdogg]

I wouldn't worry about the carbon build up.
You need to find the fuel leak.

Is it "making oil"?
And how did it run? did it smoke?

 

[OutlawRider]

I wouldn't worry about the carbon build up.
You need to find the fuel leak.

Is it "making oil"?
And how did it run? did it smoke?

Leak had to be in a line. I'm thinking the return. It was making oil when I first got it running. It's not a slow leak. Ran fine with no smoke prior. I thought it was the cp3 so replaced that. Didn't fix it so decided to replace all the injectors. Found a missing Cooper washer on injector 1. New injectors and reused those crappy Allen head banjo bolts (with new seals). Still leaked but found a lose HP line and tightened them (and ran the motor with the upper valve cover off). Couldn't find a leak. Did not use any dyes. This time, getting new everything. Banjo bolts (switched to hex head for less stripping), seals, washers, return lines.

 

[Elvis-n-texas]

I think you will be fine. I researched my injector replacement\upgrade and spoke with Kennedy Diesel; everyone reinforced to source all new hard parts, not to reuse anything.

The Isuzu motor is typical Japanese, extremely well engineered and machined to close tolerances; not like older diesels that could eat a beercan through the oil pump without a burp, and run on most anything :)

FYI; LDS purchases injectors from only one vendor. That vendor takes new nozzle design Bosch injectors made in Germany, and modifies them to fit the LB7.

Feedback from almost all posts and persons I speak to is 100% positive. My experience is more than positive; my truck makes stupid power on the highest tune, gets 19 to 20 unloaded at 65; and 10 MPH with 20K gross on the flats hauling the Yota-Toter and Rennwagon.

As a closing note, its very important to install pre-filtering and water capture. water will destroy injector tips in short order.

I use a 6.5 GM electric lift pump, a off the shelf CAT filter head, and a WIX water\fuel filter. I retain the stock filter head, but did replace it with a newer design GM part. The 99-05 stock filter heads will weep air and cause a no start. The newest GM filters are excellent for final filtration. I change all oil\filters on a 10K schedule with Rotella T6, and have done so since the 1st oil change.

Best of luck, keep us posted :)

 

[OutlawRider]

I think you will be fine. I researched my injector replacement\upgrade and spoke with Kennedy Diesel; everyone reinforced to source all new hard parts, not to reuse anything.

The Isuzu motor is typical Japanese, extremely well engineered and machined to close tolerances; not like older diesels that could eat a beercan through the oil pump without a burp, and run on most anything :)

FYI; LDS purchases injectors from only one vendor. That vendor takes new nozzle design Bosch injectors made in Germany, and modifies them to fit the LB7.

Feedback from almost all posts and persons I speak to is 100% positive. My experience is more than positive; my truck makes stupid power on the highest tune, gets 19 to 20 unloaded at 65; and 10 MPH with 20K gross on the flats hauling the Yota-Toter and Rennwagon.

As a closing note, its very important to install pre-filtering and water capture. water will destroy injector tips in short order.

I use a 6.5 GM electric lift pump, a off the shelf CAT filter head, and a WIX water\fuel filter. I retain the stock filter head, but did replace it with a newer design GM part. The 99-05 stock filter heads will weep air and cause a no start. The newest GM filters are excellent for final filtration. I change all oil\filters on a 10K schedule with Rotella T6, and have done so since the 1st oil change.

Best of luck, keep us posted :)

I am not after huge numbers power wise. I just need it to get down the road and I can’t imagine pulling more than 10k for the most part. It will be a work truck that I honestly just like driving. That said, if everything gets figured out, who did you have tune yours. I have a guy local I have thought of using just chasing decent gas mileage. There is nothing to delete on this motor.

 

[Elvis-n-texas]

Yes. Nothing to delete is great .

If your injectors new style, modified to fit LB7 they probably are 30% over stock ( going from memory, 3 or 4 years ago)

You will by default make more power over the stock injector. With the larger flow injector, you probably noticed quite a bit more torgue.

I purchased my tune through LDS.
It's an EFILIVE, 5 position tune. It's a ECU flash, not a strap on like my older Edge.

LDS can bring you up to speed on their options.

I like being able to detune back to bone stock on high temp high altitude towing, and to quickly switch to a number 4 when towing on the flats. I dont use number 5 tune. It makes stupid big power..

I just rotate the 5 position switch to the power level I need, and about 5 seconds later it takes affect.

Keep up posted. :)

 

[OutlawRider]

Yes. Nothing to delete is great .

If your injectors new style, modified to fit LB7 they probably are 30% over stock ( going from memory, 3 or 4 years ago)

You will by default make more power over the stock injector. With the larger flow injector, you probably noticed quite a bit more torgue.

I purchased my tune through LDS.
It's an EFILIVE, 5 position tune. It's a ECU flash, not a strap on like my older Edge.

LDS can bring you up to speed on their options.

I like being able to detune back to bone stock on high temp high altitude towing, and to quickly switch to a number 4 when towing on the flats. I dont use number 5 tune. It makes stupid big power..

I just rotate the 5 position switch to the power level I need, and about 5 seconds later it takes affect.

Keep up posted. :)

I have heard good things about EFI live just like you stated. Heard #5 is hard on the tranny.

 

[Elvis-n-texas]

I have heard good things about EFI live just like you stated. Heard #5 is hard on the tranny.

Yes. If I leave it on #4 tune when towing the Yota-toter and my rig and I hit the mountains and it downshifts, she limps.

My Allison needs the later updated clutch packs.. that's my 2022 project.

( burned my spare pennies on a stack of Toyo MT stickies for Rennwagen )

Keep up posted, best of luck!

 

[OutlawRider]

Passenger side is complete.

Here is the driver side.

Got them out, cleaned the cups, cleaned the carbon off the tips, new seals/washers.

New hex head banjo bolts (so much better than the Allen heads) and return lines

 

[Elvis-n-texas]

Lash those valves whilst your in there..

Mine were just off a thousand, only having 100,000 miles on it.

Looks great

 

[OutlawRider]

Did it last time (1000 miles ago).

 

[OutlawRider]

Ran it the past couple days. Put 4-500 miles on it and about 12 hours idling. Had it running all day. Seems to be doing everything right. No signs of fuel in oil yet. Really hard to read these stupid dipsticks they put in them. Oil pressure doesn’t work due to 01 ECM in 03 truck. Trying to take care of this