What Brand Injectors for Duramax?

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sbebenelli
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What Brand Injectors for Duramax?

Post by sbebenelli »

We do not do much work on diesel engines so I'd like some input on what brand of injectors I should buy for a 2005 GMC Duramax. This is my own personal truck and it needs 2 for sure but thinking about putting them all in. I priced some from Jasper. Is that a good brand to use or are there better options?
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Re: What Brand Injectors for Duramax?

Post by steven kiser »

Knowing what I know about the OEM injectors if the 05's are the same as the 04's I would use the ones from Jasper. Another point here is there is a newer fuel filter housing with a back flow preventer on it eliminating any rough running or stumbles during the first few minutes of driving. If there happens to be a fuel cooler in the line system I would strongly suggest ripping it out. They became such an issue (leaking and allowing small amounts of air to get into the fuel intake) they were eliminated in any line kit or update. Also be sure you prime the heck out of it because it doesn't take much air to burn out the pump. I usually leave the nut lock off of one of the injector lines so I can crack the nut and pump primer until I get a solid fuel flow.
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Re: What Brand Injectors for Duramax?

Post by Tim Martin »

steven kiser wrote:Knowing what I know about the OEM injectors if the 05's are the same as the 04's I would use the ones from Jasper. Another point here is there is a newer fuel filter housing with a back flow preventer on it eliminating any rough running or stumbles during the first few minutes of driving. If there happens to be a fuel cooler in the line system I would strongly suggest ripping it out. They became such an issue (leaking and allowing small amounts of air to get into the fuel intake) they were eliminated in any line kit or update. Also be sure you prime the heck out of it because it doesn't take much air to burn out the pump. I usually leave the nut lock off of one of the injector lines so I can crack the nut and pump primer until I get a solid fuel flow.
Excellent tips here.

The last time I checked with Jasper for a set of injectors for the Duramax, they were not available. So, other than BD or Dynomite as aftermarket rebuilders (which we have used and have had some issues with), their is little else except for the OEM which is what we are using more of due to availability and warranty benefits.
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Re: What Brand Injectors for Duramax?

Post by steven kiser »

The OEM injectors I've used have all seemed to fail more frequent than I would like. I've found life expectancy to be around 70K. Another thing is make sure the old injector bottoming seals are removed and new ones used. If you drop a new one and can't find it don't even consider for a second to use an old one. They are machined to be secure when you loch down the injector. A used one can allow a small amount of blow by then it turns into a suction when engine is shut down at the right time. If that happens it's the beginning of possible collapsed or melted pistons. I'm almost sure I read an article about Jasper selling re manufactured injectors. A lot of shops want to replace the feed tubes when injectors are replaced. If they haven't been overtightened then It's a huge waste of money. As they are removed look at the line seat and slide the nut back looking for any signs of stress. These can be a real SOB to bleed so take your time and don't give up. I've had a few that took me about 20 minutes to bleed out. It's a lift style pump so you cant leave bleeder on top of filter open. I make sure filter is full when I install it then pump the hell out of the primer, open the bleeder, pump it again, open bleeder, pump it again. I try to compare it to allowing patch glue drying prior to placing patch on the tire. The longer the better. Patience is the key and accepting there may be repetition. It may take a bit of running and stumbling to get all the air out. Don't try to push it through by playing with the as pedal. Another quickie, when you open up the harnesses to move them inspect them thoroughly and I use a liberal amount of electrical grease putting them together. There isn't any extra length so the harness needs to be exact.
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Re: What Brand Injectors for Duramax?

Post by Tim Martin »

steven kiser wrote:The OEM injectors I've used have all seemed to fail more frequent than I would like. I've found life expectancy to be around 70K. Another thing is make sure the old injector bottoming seals are removed and new ones used. If you drop a new one and can't find it don't even consider for a second to use an old one. They are machined to be secure when you loch down the injector. A used one can allow a small amount of blow by then it turns into a suction when engine is shut down at the right time. If that happens it's the beginning of possible collapsed or melted pistons. I'm almost sure I read an article about Jasper selling re manufactured injectors. A lot of shops want to replace the feed tubes when injectors are replaced. If they haven't been overtightened then It's a huge waste of money. As they are removed look at the line seat and slide the nut back looking for any signs of stress. These can be a real SOB to bleed so take your time and don't give up. I've had a few that took me about 20 minutes to bleed out. It's a lift style pump so you cant leave bleeder on top of filter open. I make sure filter is full when I install it then pump the hell out of the primer, open the bleeder, pump it again, open bleeder, pump it again. I try to compare it to allowing patch glue drying prior to placing patch on the tire. The longer the better. Patience is the key and accepting there may be repetition. It may take a bit of running and stumbling to get all the air out. Don't try to push it through by playing with the as pedal. Another quickie, when you open up the harnesses to move them inspect them thoroughly and I use a liberal amount of electrical grease putting them together. There isn't any extra length so the harness needs to be exact.
Again, some excellent ideas and tips here from an experienced tech.

So far, we have had no issues with OEM injectors. Will continue to use them at this point.
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Re: What Brand Injectors for Duramax?

Post by sbebenelli »

Thank you for the info. Like I said this is my truck. I need a diesel like I need a hole in the head. I've owned it for 7 years and used to pull a camper with it. I have since sold the camper but it's such a nice truck I hate to sell it. It's 100% completely rust free and living in the rust belt I park it for the winter.

That being said I'm not going to do anything with it till spring but wanted to get a game plan in place so I knew what needed to be done.
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Re: What Brand Injectors for Duramax?

Post by Tim Martin »

Well, like I said, we use OEM partly because of availability and because of warranty. Not every shop has a good GM dealer close by like we do. So, that might make a difference for some of us because I admit that if this dealer was farther away, we might look at other options.
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Re: What Brand Injectors for Duramax?

Post by sbebenelli »

The Jasper injectors are $310.00 and the dealer injectors are $312.66.

I guess either one should be OK.
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Re: What Brand Injectors for Duramax?

Post by sbebenelli »

I ended up getting brand new set of Bosch injectors from InjectorsDirect.com. These were barely more for new than what Jasper wanted for remans. They have a 2 year warranty. The downside to their warranty is if you were to use them on a customer vehicle is that if you have a bad injector you send it to them and they check it on their injector test stand. If it checks OK they charge you a fee for checking it and send it back to you.

With this being my own truck that's not a big deal to me.

They also have new Bosch fuel pressure regulators for half of what my cost was at the dealer. These are the same thing that are in the GM box.

Truck starts good and runs smooth. Injector balance rates are all at 0.
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Re: What Brand Injectors for Duramax?

Post by scgms1 »

Sorry for getting here late on the reply sbebenelli...

The only time I ever replace a whole set of injectors on Duramax's would be for the LB7 engines which were made from 2001 - Mid 2004. Mid 2004 they switched to the LLY engines. These have proven to be very reliable and compared to the internal injectors found on the LB7's - there is no comparison. I've replaced many/multiple sets of injectors on LB7's and individual injectors on LLY, LBZ, LLM... and subsequent RPO codes of the Duramax engine.

I've heard tales from dealer techs and customers that the newer dual-lobe injector pumps used from 2010 on up have had some catastrophic failures necessitated a complete fuel system rebuild, including all 8 injectors. See GM #16-NA-102 for details. The older tri-lobe pumps had a handful of failures, but nothing like this.

As far brands go, I'm hesitant to deviate from factory, as in experimenting on customers vehicles to find a cheaper substitute for something I know will work. Especially on LLY's and up, where they are replaced on an individual basis. I've got quite a few DMax's that are above the 500k mark, and your experience may differ than mine, but I replace individual injectors on anything other than the original LB7's. (which are junk, and still are)

As a side note. It's interesting that Bosch has gone to selling directly and cutting out their network of rebuilders. My understanding was Bosch had certain requirements to become an authorized rebuilder, including a substantial amount of money for testing equipment...I heard somewhere in the neighborhood of 500k. In order to get replacement parts directly from them (Bosch) you had to make this investment and they also limited your sales to a 60 mile radius. This would mean no internet sales. I've heard of some companies circumventing this, but...
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Re: What Brand Injectors for Duramax?

Post by scgms1 »

Here's an example of what I'm talking about. A customer who owns a 2004 DMax, 6.6L VIN 2, LLY engine. I started to work on this vehicle when it had 187k back in 1/2010.

Sporadic fuel filter replacements, usually when he shows up for things he's not able to take care of.

6/2013, 302k, cylinder 5 injector. A FPR - Fuel Pressure Regulator was replaced at that time due to a erratic idle. This was looked at prior to the injector replacement/problem.

11/2016, 426k, cylinder 4 injector replaced.

So, 2 injectors in 426,000 miles. That's not bad considering his lack of fuel filter replacements. :D
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Re: What Brand Injectors for Duramax?

Post by sbebenelli »

scgms1 wrote:
As a side note. It's interesting that Bosch has gone to selling directly and cutting out their network of rebuilders. My understanding was Bosch had certain requirements to become an authorized rebuilder, including a substantial amount of money for testing equipment...I heard somewhere in the neighborhood of 500k. In order to get replacement parts directly from them (Bosch) you had to make this investment and they also limited your sales to a 60 mile radius. This would mean no internet sales. I've heard of some companies circumventing this, but...
According to them they have invested over $500,000 in the latest state of the art equipment in order to properly clean, test, and calibrate injectors for Duramax, Cummins, and Power Stroke engines. https://www.injectorsdirect.com/about-us/

They are alsso in the process of building a new facility. https://www.injectorsdirect.com/breaks- ... -facility/

They was professional, shipped quick and I'd buy from them again.
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Re: What Brand Injectors for Duramax?

Post by sbebenelli »

scgms1 wrote:Here's an example of what I'm talking about. A customer who owns a 2004 DMax, 6.6L VIN 2, LLY engine. I started to work on this vehicle when it had 187k back in 1/2010.

Sporadic fuel filter replacements, usually when he shows up for things he's not able to take care of.

6/2013, 302k, cylinder 5 injector. A FPR - Fuel Pressure Regulator was replaced at that time due to a erratic idle. This was looked at prior to the injector replacement/problem.

11/2016, 426k, cylinder 4 injector replaced.

So, 2 injectors in 426,000 miles. That's not bad considering his lack of fuel filter replacements. :D
I had 2 injectors go bad within a month of each other. The injector balance rates of all the others were at least +7 or -7 and have been for awhile. I take this truck out of town pulling my boat. It was a no brainier to me to replace all of them for piece of mind. All the balance rates are 0 now, truck runs smoother and is quieter and I will not have to worry about it for as long as I own the truck.
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Re: What Brand Injectors for Duramax?

Post by scgms1 »

sbebenelli wrote:
I had 2 injectors go bad within a month of each other. The injector balance rates of all the others were at least +7 or -7 and have been for awhile. I take this truck out of town pulling my boat. It was a no brainier to me to replace all of them for piece of mind. All the balance rates are 0 now, truck runs smoother and is quieter and I will not have to worry about it for as long as I own the truck.
I can't argue with success. I'm glad it all worked out for you. What you described, I've never seen, and I'm sure I haven't seen a lot of things. I am pretty familiar with DMax's though and I've never seen balance rates all at +/- 7mm3, or above on any DMax, and this includes the LB7's. I've also never seen balance rates after injector replacements all at 0mm3. Would have any snapshots of what was happening before and after the injector replacement that you could send me? I'm interested in seeing Engine Data 2 PID's.

Have you ever added anything to the fuel system? Done injector cleaning? Where do you buy your fuel from? What's the API rating, have you ever had it tested? Is it ultra low Sulphur from a name brand station? I've also seen differences in fuel and its' effects on gas engines and injectors from across the nation. I'd be concerned based on what you said.

Thanks,
Scott
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Re: What Brand Injectors for Duramax?

Post by sbebenelli »

I do not have any screenshots of before. I use low sulfur usually from Murphy's. It's all low sulfur around here. I did not use an additive before but I'm using Stanadyne now and will continue doing so.

Here is the after balance rates. I stand corrected 3 of them are at + or - 1. When I got done they were all at 0 but I didn't monitor them very long. I just wanted to see what they read.
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injector.jpeg
injector.jpeg (58.58 KiB) Viewed 7273 times
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Re: What Brand Injectors for Duramax?

Post by scgms1 »

OK, that make sense. Is that Snap-on? It looks like they round up, or down, the balance rates. Anything below .5mm3 is 0 and above is 1mm3. 2.5mm3 would show 3 I'm assuming.

Here's what GM's software looks like from a typical LB7 with injector problems...
LB7 Before.JPG
LB7 Before.JPG (110.5 KiB) Viewed 7271 times
And then after replacing the injectors...It's good, but none are reading 0. None of yours would be reading 0 either, but that's some anomaly with the way your tool processes the Balancing Rate PID's.
LB7 After.JPG
LB7 After.JPG (117.72 KiB) Viewed 7271 times
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