lb7 injector tubes leaking

Vmyrhaug

Member
Mar 6, 2016
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i have 03 lb7, have changed injectors and injector tubes. have been on road for 3 months now.
but, i've had 3 injector tubes that start leaking. and they leak alot.
the nut is torqued, when i loose up and retorque, they seal. the if i do a wot run, 1 start to leak again. never the same, but it always one of three.
does anybody had this problem?

injector tubes are not gm, but cheap aftermarked.
 

TheBac

Why do I keep doing this?
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Apr 19, 2008
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If you're talking about the injector cups, chances are you didnt seal the cup to the head good enough, or wait long enough for the loctite to set up before running the engine.
I do agree that using aftermarket cups isnt a good idea unless they are the screw-in type.

Moved to LB7 section, btw.
 
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Vmyrhaug

Member
Mar 6, 2016
151
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Norway
If you're talking about the injector cups, chances are you didnt seal the cup to the head good enough, or wait long enough for the loctite to set up before running the engine.
I do agree that using aftermarket cups isnt a good idea unless they are the screw-in type.

Moved to LB7 section, btw.
its the fuel lines from fuel rail too injector i'm having trouble with. i bought ceap aftermarked ones, and they start too leak on wot, they do not come loose, but loose them up and retorque, they stop leaking for a while.
old stock ones is a bit rusty, will they work if i clean then up?
 

2004LB7

Well-known member
Dec 15, 2010
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you can clean the stock ones. ultrasonic works good. rinse and dry well before use

you can probably do this two or three times, maybe more if they aren't in bad shape before needing to replace them.
 
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TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,271
1,565
113
Mid Michigan
its the fuel lines from fuel rail too injector i'm having trouble with. i bought ceap aftermarked ones, and they start too leak on wot, they do not come loose, but loose them up and retorque, they stop leaking for a while.
old stock ones is a bit rusty, will they work if i clean then up?
Oh, the feed lines. Yep, do not use aftermarket feed lines. Yes, you can clean/reuse your old ones, as Jason explained.
 
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Bdsankey

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Feb 1, 2018
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Not all the aftermarket lines are created equal. I've used Fleece and DHD lines for years without a failure but the cheaper lines have given issues. The best lines IMO are straight from the dealership.