Injector and Fuel filter questions

[GeoffM]

Hi all,

Just got my 2016 Yukon xl Denali back from a transmission replacement. About 100 miles into a 1000 mile trip my truck started running rough. Got it back home to a dealer who diagnosed it as a bad #6 injector.
Dealer replaced that single injector($1100). Put it back together and #8 started acting up($800).

Averaging ~$1000 a injector at this rate, I told them nevermind and give it back.

I have the other 7 injectors arriving today. Replacement will have to hold off until the following weekend, but:
Presumably there is some single use gasket on the injector they're already replaced. You aren't supposed to just pull it out of the head and the fuel rail and reinsert it, correct? If not, is mileage a concern? There's maybe 50 miles on the replacement injector I intend on reusing.

I ordered this gasket kit(2): https://www.rockauto.com/en/moreinfo.php?pk=13456197&jsn=933 as that's what was on the dealers quote. I see the dust boots for the injector to head connection. The other seals, they go on the injector correct? Is there a procedure for removing the old seals and sliding the new on?

What is the torque spec for retightening the fuel rails?
Does the intake tightening have a pattern, and does it have a torque spec?

Fuel filter:
Checking the normal sites (autozone etc)... they don't return a result for a fuel filter. Is the only filter really the intake screen on the pump? That seems silly but I figured I'd ask.


Edit: I ordered the fuel rail and fuel line/hose, as those are single use only. (12677002 and 12677004). I'm also doing the spark plugs as it's got about 144k miles.
I'm normally a Honda guy, this is my first American car/GM. Are there other parts I should be replacing when the diagnosis is "engine running poorly"?

 

[ReaperHWK]

believe there are a few youtube videos on injector replacement, I'd do a search first there.

I might have to change my #8 injector soon, so I'll find out!

Also I know as far as your gasket and ring questions, there is a section in the Haynes repair manual I have that goes over that. Swing by autozone and look at the Haynes manual for the injector replacement section for 2015+ silverados, it's the same engine. You really should be looking at the manual and getting the specs there for this job.

I can't believe they charge $1000 for that job! That is nuts.

 

[GeoffM]

believe there are a few youtube videos on injector replacement, I'd do a search first there.

I might have to change my #8 injector soon, so I'll find out!

Also I know as far as your gasket and ring questions, there is a section in the Haynes repair manual I have that goes over that. Swing by autozone and look at the Haynes manual for the injector replacement section for 2015+ silverados, it's the same engine. You really should be looking at the manual and getting the specs there for this job.

I can't believe they charge $1000 for that job! That is nuts.

I've done a bit of searching since yesterday. I can't find a definitive answer for if I need to replace the seals for the new injector if I remove it from the head. My goal is to try and leave it in the head and just replace the fuel rail side seals.

If not: The head side seals are a bit complicated. I've ordered the sizing kit and I'm hoping it'll be here on Monday. In the event it's not I might just make the "compression" fitting on my lathe or use my reloading tools.

The process is essentially:
1. Cut off the old teflon rings
2. Size up the new seals
3. Slide them onto the injector
4. Compress them onto the injector

Fun stuff!

 

[OR VietVet]

Always replace the seals and everything else that you remove, that has anything to do with sealing. The fuel filter is in the tank and part of the pump.

 

[ReaperHWK]

I see that the whole rail has to come out with 4 injectors. I get that. They sell the seals as a kit. Why are you measuring them? There is a part number for your VIN.

 

[ReaperHWK]

so I ordered the correct fuel injector from tje dealer with my VIN. OEM part so it fits. The injector also comes with the seals for the other 3 injectors on the rail. You need to replace all those 3 Teflon seals, o ring, and support ring. The new injector comes with them installed already. To get the new Teflon seals on the other 3 injectors you need a special tool. This one works:

6pcs GM245 Fuel Injector Seals Tool For Subaru, GM Replace EN-49245, EN-51105, 18683AA000 https://a.co/d/48jjWBH

And yes if you remove ANY injector per the manual it needs new seals.

 

[GeoffM]

so I ordered the correct fuel injector from tje dealer with my VIN. OEM part so it fits. The injector also comes with the seals for the other 3 injectors on the rail. You need to replace all those 3 Teflon seals, o ring, and support ring. The new injector comes with them installed already. To get the new Teflon seals on the other 3 injectors you need a special tool. This one works:

6pcs GM245 Fuel Injector Seals Tool For Subaru, GM Replace EN-49245, EN-51105, 18683AA000 https://a.co/d/48jjWBH

And yes if you remove ANY injector per the manual it needs new seals.

I ordered that injector tool kit. It should arrive today. If you read the reviews there's a few saying that the compression/down sizer tool doesn't fit correctly.
If it doesn't, I was going to try alternative methods (bullet reseater for a .308, lathe and making my own tool, etc).

However, the Haynes manual has a good idea: Use a piece of vinyl tubing over the seal that is installed on the injector to get it to shrink back down. They recommend leaving it like that for a few hours to make sure it shrinks properly.
My dealer was nice enough to only replace the single injector and not do the seals for the remaining injectors. They were doubled up or crisscrossed. Once I have this back together I'm gonna go have a talk with them.

Side note for you: Be very careful with the injector rails. It took my dealer 3 days to get the right side out. Since that was only a week ago I was able to lift it out with very little resistance.
Despite being careful and going slow(5 hours!), I bent the left/drivers side fuel rail. As luck would have it that is the rail that is difficult to find.

 

[ReaperHWK]

I ordered that injector tool kit. It should arrive today. If you read the reviews there's a few saying that the compression/down sizer tool doesn't fit correctly.
If it doesn't, I was going to try alternative methods (bullet reseater for a .308, lathe and making my own tool, etc).

However, the Haynes manual has a good idea: Use a piece of vinyl tubing over the seal that is installed on the injector to get it to shrink back down. They recommend leaving it like that for a few hours to make sure it shrinks properly.
My dealer was nice enough to only replace the single injector and not do the seals for the remaining injectors. They were doubled up or crisscrossed. Once I have this back together I'm gonna go have a talk with them.

Side note for you: Be very careful with the injector rails. It took my dealer 3 days to get the right side out. Since that was only a week ago I was able to lift it out with very little resistance.
Despite being careful and going slow(5 hours!), I bent the left/drivers side fuel rail. As luck would have it that is the rail that is difficult to find.

Thanks for the tips. Yes I saw that method in the haynes manual but wanted to use the tool. I’ll probably get to this job next weekend.

Are you all done? How’s it run.

 

[GeoffM]

Thanks for the tips. Yes I saw that method in the haynes manual but wanted to use the tool. I’ll probably get to this job next weekend.

Are you all done? How’s it run.

Nope. Try as I might to be gentle I bent the left side fuel rail.
That's the side you (apparently) can't just order. I suspect because it has the fuel rail pressure sensor on it.
I found one on Amazon that should get here next Monday (yay rural living!). I think it is for the L87 vs the L86. If it visually fits I might try and install it.

All that being said it is a slight bend. I might try and bend it back or install it as is, depending on parts availability.

Funnily enough, I ran across this TSB trying to find the fuel rail: https://static.nhtsa.gov/odi/tsbs/2020/MC-10176632-9999.pdf

 

[ReaperHWK]

Nope. Try as I might to be gentle I bent the left side fuel rail.
That's the side you (apparently) can't just order. I suspect because it has the fuel rail pressure sensor on it.
I found one on Amazon that should get here next Monday (yay rural living!). I think it is for the L87 vs the L86. If it visually fits I might try and install it.

All that being said it is a slight bend. I might try and bend it back or install it as is, depending on parts availability.

Funnily enough, I ran across this TSB trying to find the fuel rail: https://static.nhtsa.gov/odi/tsbs/2020/MC-10176632-9999.pdf

Good to know about that TSB. I’ll keep the new injectors sealed in the package and just verify with the old ones before I replace. Dealer didn’t seem to think there is going to be an issue with the PN they sold me.

Also I’m replacing the right side rail and injectors only so I don’t have to mess with the pressure sensor luckily.

Thanks.