Injector replacement Help 2017 6.2l L86

[Dakota Murphy]

So I got a l86 and got the notorious P050d code. This only happens when it’s in dual pulse mode on the cold start.  I’m getting prepared to pull the injectors and get the part number to order. I’ve seen several videos and guides of people installing these so I know basically what to do but have a couple questions on little things. GM does not say to lube or put anything on the seals of the new injectors. I’ve seen where people have and people haven’t. Any advice on this? Also I already have the too high pressure lines. I don’t need to replace the 3rd low pressure line right?  Is this somthing you’d replace anyway. I’m going to do all 8 injectors at once. 

Edited April 11, 2025 by Dakota Murphy

[newdude]

1 hour ago, Dakota Murphy said:

So I got a l86 and got the notorious P050d code. This only happens when it’s in dual pulse mode on the cold start.  I’m getting prepared to pull the injectors and get the part number to order. I’ve seen several videos and guides of people installing these so I know basically what to do but have a couple questions on little things. GM does not say to lube or put anything on the seals of the new injectors. I’ve seen where people have and people haven’t. Any advice on this? Also I already have the too high pressure lines. I don’t need to replace the 3rd low pressure line right?  Is this somthing you’d replace anyway. I’m going to do all 8 injectors at once. 

 

 

6.2 GM suggests you match the old p/n flow as the rails are set up for balance from the factory.  Low, nominal and high.  However, that said, if you can't verify what flow they are, they say to order 8 nominal flow injectors.  Current # for those is 19420316.

 

"Note: If for some reason the injector has been removed, discarded or have all injectors on the bench and are not sure which one goes where, then the best thing to do is order the “NOM FLOW” injector part number as shown above, in the quantity you need, and install them in the engine. In this case you would order what is shown below.

When fuel rails are assembled at the supplier, the injector installed in the fuel rail can be nominal, low or high flow injectors. This is done to try and get an even balance or flow across the fuel rail for emission requirements. Also, the replacement injector kits will be a different part number than the injectors, and also that a kit may contain one of several different injector part numbers."

 

 

Do NOT lubricate the tip seals.  The only thing GM calls to lube with anything is the "socket" on the rail where each injector sits, and to only lightly lubricate with clean engine oil.  There is clear warnings on the rail install and removal instructions to not lubricate the injector tip seals.  

 

Pipes.  You just need the two in the valley.  The pipe from the pump to the "S" center pipe, and the "S" center pipe itself as well.  The third line is only if you are planning to remove or replace the high pressure pump which is not necessary for injector replacement.  

[Dakota Murphy]

Thank you for the finer details. I knew about the nominal flow if they couldn’t be matched but wasn’t gonna do anything until pulling and seeing. The lube was the main question and I seen where people had, but I wanted to know what exactly gm wanted there. I would think the lube would actually attract more carbon than without it over time. This helps a bunch thanks again! 
 

10 hours ago, newdude said:

 

 

6.2 GM suggests you match the old p/n flow as the rails are set up for balance from the factory.  Low, nominal and high.  However, that said, if you can't verify what flow they are, they say to order 8 nominal flow injectors.  Current # for those is 19420316.

 

"Note: If for some reason the injector has been removed, discarded or have all injectors on the bench and are not sure which one goes where, then the best thing to do is order the “NOM FLOW” injector part number as shown above, in the quantity you need, and install them in the engine. In this case you would order what is shown below.

When fuel rails are assembled at the supplier, the injector installed in the fuel rail can be nominal, low or high flow injectors. This is done to try and get an even balance or flow across the fuel rail for emission requirements. Also, the replacement injector kits will be a different part number than the injectors, and also that a kit may contain one of several different injector part numbers."

 

 

Do NOT lubricate the tip seals.  The only thing GM calls to lube with anything is the "socket" on the rail where each injector sits, and to only lightly lubricate with clean engine oil.  There is clear warnings on the rail install and removal instructions to not lubricate the injector tip seals.  

 

Pipes.  You just need the two in the valley.  The pipe from the pump to the "S" center pipe, and the "S" center pipe itself as well.  The third line is only if you are planning to remove or replace the high pressure pump which is not necessary for injector replacement.  

 

Edited April 12, 2025 by Dakota Murphy

[rlcole321]

I also suggest cleaning the injector bores very well, I did mine, although they say no lube on the seals, I did put a "Tiny" bit of the 0W20 on them just to barely wet them. I didn't have any issues, just make sure you clean the bores, I used intake cleaner, and a nylon bore brush, then flushed with Brake Cleaner and dry. If for some reason one or more of the Teflon seals are damaged on new injectors (it happened to me) be sure to watch videos on how to install them, very critical!!