Replacing LT1 Injectors to LT4 ones

Eldi Z · 09-09-2021, 06:17 PM

For those who have done the change in their motors, did you / your shop have any mechanical challenges while replacing the injectors?

Since the Injectors are GDI type, I hear about DI type injectors in general, being stubborn to pull out and often get damaged during the process.

My source of information is coming from a number of European engines - mainly VW-Audi with their TSI engines - Just interested to know if this is also the case with our engines.

Joshinator99 · 09-09-2021, 06:32 PM

Quote:

Originally Posted by Eldi Z

For those who have done the change in their motors, did you / your shop have any mechanical challenges while replacing the injectors?

Since the Injectors are GDI type, I hear about DI type injectors in general, being stubborn to pull out and often get damaged during the process.

My source of information is coming from a number of European engines - mainly VW-Audi with their TSI engines - Just interested to know if this is also the case with our engines.

I’ve changed injectors twice now, no issues. Just make sure you replace the injector seals if the injectors are not new. And always replace the high pressure fuel pipes, every time you take that system apart.

Eldi Z · 09-10-2021, 05:57 PM

Quote:

Originally Posted by Joshinator99

I’ve changed injectors twice now, no issues. Just make sure you replace the injector seals if the injectors are not new. And always replace the high pressure fuel pipes, every time you take that system apart.

Thanks for the heads-up. When I order new injectors, do they come with the seals, or do I have to order the seals separately?
I am planning to upgrade my fuel system to all-LT4 parts, so the 2 Hard-Fuel Pressure pipes on the motor going to the HPFP are going to be replaced to new LT4 Part# ones.

While we are at it, another quick question about the LT4 injectors:

I saw there are 3 types of injectors, all designated as a correct fit in terms of the Part#s at least:
"Low Flow", "Nominal" and "High Flow" - Which of the 3 types is say the "stock" OEM that is supplied in a typical ZL1 for instance? (or a CTS-V, Z06 for that matter...)
Which type Part# should I get? The "High Flow", "Nominal" ? I am a bit confused on this - maybe you can set me straight.

Joshinator99 · 09-10-2021, 07:35 PM

Quote:

Originally Posted by Eldi Z

Thanks for the heads-up. When I order new injectors, do they come with the seals, or do I have to order the seals separately?
I am planning to upgrade my fuel system to all-LT4 parts, so the 2 Hard-Fuel Pressure pipes on the motor going to the HPFP are going to be replaced to new LT4 Part# ones.

While we are at it, another quick question about the LT4 injectors:

I saw there are 3 types of injectors, all designated as a correct fit in terms of the Part#s at least:
"Low Flow", "Nominal" and "High Flow" - Which of the 3 types is say the "stock" OEM that is supplied in a typical ZL1 for instance? (or a CTS-V, Z06 for that matter...)
Which type Part# should I get? The "High Flow", "Nominal" ? I am a bit confused on this - maybe you can set me straight.

New injectors will have new seals on them, so you should be good to go.

The flow rating doesn’t matter , but you have to run the same rating on all 8 injectors. So if you go with “Nominal”, then all 8 must be “Nominal”. Part number 12682374 is the most common number I see for them.

Eldi Z · 09-11-2021, 06:15 AM

[QUOTE=Joshinator99;11069021

The flow rating doesn’t matter , but you have to run the same rating on all 8 injectors. So if you go with “Nominal”, then all 8 must be “Nominal”. Part number 12682374 is the most common number I see for them.[/QUOTE]

Very well.
I found this Part# as the current Part#:
12668397

https://fuelinjectorconnection.com/c...nt-pn-12682374

Another question: How important / necessary is a BaP? I am not a fan of "artificial" upping of voltages on the LPFP and over-stressing it, if it is not absolutely critical for proper fuel delivery.

arpad_m · 09-11-2021, 06:39 AM

Quote:

Originally Posted by Eldi Z

Very well.
I found this Part# as the current Part#:
12668397

https://fuelinjectorconnection.com/c...nt-pn-12682374

Another question: How important / necessary is a BaP? I am not a fan of "artificial" upping of voltages on the LPFP and over-stressing it, if it is not absolutely critical for proper fuel delivery.

As far as I know, it isn't used for boosting voltage so much as preventing voltage drop at high loads, which helps preserve a healthy safety margin. Whether or not it's "critical", I am not able to tell, but (as per Ted Jannetty's advice) my car has one to make sure it's on the safe side of fueling.

Joshinator99 · 09-11-2021, 08:50 AM

Quote:

Originally Posted by Eldi Z

Very well.
I found this Part# as the current Part#:
12668397

https://fuelinjectorconnection.com/c...nt-pn-12682374

Another question: How important / necessary is a BaP? I am not a fan of "artificial" upping of voltages on the LPFP and over-stressing it, if it is not absolutely critical for proper fuel delivery.

Depends on your desired power level IMO. If you're going for low to mid 600s WHP then you can generally tune the FSCM with the LT4 in tank pump and be fine. If you want more you definitely want the JMS.

KingLT1 · 09-11-2021, 09:05 AM

The JMS doesn't really put any strain on the fuel pump since it simply supplies more voltage to the system controller and not the pump directly. It activates when you hit a certain throttle percentage or boost level depending on how it's set up. The fuel pump controller is a Pulse Width Modulated system and will safely bump up the voltage to the pump.

LiqTenExp · 09-11-2021, 09:13 AM

Make sure to get an injector seal tool to pre-size them before insertion! Something like this: https://www.amazon.com/gp/product/B088TLZBRT The part labeled 245-4 in the picture is really all you need for new injectors.

Check here for pipe part #s: https://www.camaro6.com/forums/showp...9&postcount=17 I replaced all of LT4 injectors with a new set this year, one in Cylinder #3 was causing misfires, did the whole set.

SSUNDVL · 09-11-2021, 01:33 PM

idk about injector seal tool, if they are new you should be able to just install, it was really easy from what I remember. Sometimes they are a bit tricky to remove, I used a wrench as leverage to pry the fuel rails off and they popped right out.

LiqTenExp · 09-11-2021, 02:19 PM

Quote:

Originally Posted by SSUNDVL

idk about injector seal tool, if they are new you should be able to just install, it was really easy from what I remember. Sometimes they are a bit tricky to remove, I used a wrench as leverage to pry the fuel rails off and they popped right out.

It compresses/shapes the teflon seals so they don't hang up on install. Service manual calls to use one...

SSUNDVL · 09-11-2021, 03:20 PM

Quote:

Originally Posted by LiqTenExp

It compresses/shapes the teflon seals so they don't hang up on install. Service manual calls to use one...

Yes if you are re-installing used ones, but they are preinstalled on new injectors so you don't need it. Also plenty of people remove/replace injectors without new seals especially if it has not been driven much since initial install but if reinstalling you prob should since you are dealing with fuel and a leak could be bad quick.

LiqTenExp · 09-11-2021, 04:11 PM

Quote:

Originally Posted by SSUNDVL

Yes if you are re-installing used ones, but they are preinstalled on new injectors so you don't need it. Also plenty of people remove/replace injectors without new seals especially if it has not been driven much since initial install but if reinstalling you prob should since you are dealing with fuel and a leak could be bad quick.

You are missing of the purpose of the tool completely.

That tool (245-4) does not install anything, it shapes/compresses the teflon seals AFTER installation or on brand new injectors prior to insertion into the heads.

Not shaping/compressing them prior to insertion with new seals can cause them to drag and get damaged causing air leaks. I would never reinstall the injectors w/o replacing the seals. On an GenV there is just way too much effort to get to them to warrant taking that chance if they leak.

SSUNDVL · 09-11-2021, 04:25 PM

I don't think it is do or die, it might extend life of seal but by how much and how long does the seal last without? I doubt by not compressing it you will leak. I would be curious to see how many people do this vs just installing and never have issues. I'm guessing most install them out of box and don't see issues.

09-09-2021, 06:17 PM	#1
Eldi Z Drives: 17' 1SS 1LE GBA-Black Join Date: Mar 2017 Location: TLV Posts: 810	Replacing LT1 Injectors to LT4 ones For those who have done the change in their motors, did you / your shop have any mechanical challenges while replacing the injectors? Since the Injectors are GDI type, I hear about DI type injectors in general, being stubborn to pull out and often get damaged during the process. My source of information is coming from a number of European engines - mainly VW-Audi with their TSI engines - Just interested to know if this is also the case with our engines.

09-11-2021, 09:05 AM	#8
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,797	The JMS doesn't really put any strain on the fuel pump since it simply supplies more voltage to the system controller and not the pump directly. It activates when you hit a certain throttle percentage or boost level depending on how it's set up. The fuel pump controller is a Pulse Width Modulated system and will safely bump up the voltage to the pump. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

09-11-2021, 09:13 AM	#9
LiqTenExp Drives: 2017 ZL1 Join Date: Jan 2017 Location: NJ Posts: 905	Make sure to get an injector seal tool to pre-size them before insertion! Something like this: https://www.amazon.com/gp/product/B088TLZBRT The part labeled 245-4 in the picture is really all you need for new injectors. Check here for pipe part #s: https://www.camaro6.com/forums/showp...9&postcount=17 I replaced all of LT4 injectors with a new set this year, one in Cylinder #3 was causing misfires, did the whole set. __________________ 2017 Camaro ZL1 Coupe M6 (847whp Dynojet on 93)

09-11-2021, 06:15 AM	#5
Eldi Z Drives: 17' 1SS 1LE GBA-Black Join Date: Mar 2017 Location: TLV Posts: 810	[QUOTE=Joshinator99;11069021 The flow rating doesn’t matter , but you have to run the same rating on all 8 injectors. So if you go with “Nominal”, then all 8 must be “Nominal”. Part number 12682374 is the most common number I see for them.[/QUOTE] Very well. I found this Part# as the current Part#: 12668397 https://fuelinjectorconnection.com/c...nt-pn-12682374 Another question: How important / necessary is a BaP? I am not a fan of "artificial" upping of voltages on the LPFP and over-stressing it, if it is not absolutely critical for proper fuel delivery.

09-11-2021, 01:33 PM	#10
SSUNDVL Drives: 2016 Camaro SS Join Date: Jul 2020 Location: Dallas, TX Posts: 149	idk about injector seal tool, if they are new you should be able to just install, it was really easy from what I remember. Sometimes they are a bit tricky to remove, I used a wrench as leverage to pry the fuel rails off and they popped right out.

09-11-2021, 04:25 PM	#14
SSUNDVL Drives: 2016 Camaro SS Join Date: Jul 2020 Location: Dallas, TX Posts: 149	I don't think it is do or die, it might extend life of seal but by how much and how long does the seal last without? I doubt by not compressing it you will leak. I would be curious to see how many people do this vs just installing and never have issues. I'm guessing most install them out of box and don't see issues.

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