So I ice picked #2 a couple months ago after the truck went into the typical limp mode on the side of the road. 10 minutes later, all was good again. It's been in the 20's here the past few days, but I've had no problems out of the truck. Drove it 40 miles round trip to pick up my trailer with my camaro on it. Stopped at a friend's house for a little while. Got back in and started it up.

Under light throttle around 1400 rpms, there's a loud injector knocking sound. I drove the truck around for a while, and it didn't go away, and is consistent under light throttle, the same rpm range no matter the gear. Absolutely no codes thrown, no limp mode, no excess smoke, but it does seem to be slightly down on power. I'm 6 hours from home with a trailer/camaro on the back and needed to leave in the morning.

Any ideas? Do I just ice pick #7 as a shot in the dark? Without it throwing codes, how do I figure out which injector is bad with my EFI Live?

Oh yeah, this is my 04.5 LLY

Mine has been doing the same thing, took it to the dealer and they said the balance rates were ok and could not find any codes etc........ of course they said they could not find out what was wrong, it is out of warranty.

Mine has been doing the same thing, took it to the dealer and they said the balance rates were ok and could not find any codes etc........ of course they said they could not find out what was wrong, it is out of warranty.



What did your dealer charge to check the balance rates if you don't mind me asking?

So I ice picked #2 a couple months ago after the truck went into the typical limp mode on the side of the road. 10 minutes later, all was good again. It's been in the 20's here the past few days, but I've had no problems out of the truck. Drove it 40 miles round trip to pick up my trailer with my camaro on it. Stopped at a friend's house for a little while. Got back in and started it up.

Under light throttle around 1400 rpms, there's a loud injector knocking sound. I drove the truck around for a while, and it didn't go away, and is consistent under light throttle, the same rpm range no matter the gear. Absolutely no codes thrown, no limp mode, no excess smoke, but it does seem to be slightly down on power. I'm 6 hours from home with a trailer/camaro on the back and needed to leave in the morning.

Any ideas? Do I just ice pick #7 as a shot in the dark? Without it throwing codes, how do I figure out which injector is bad with my EFI Live?

Oh yeah, this is my 04.5 LLY

I'd pick the #7 injector. And check the balance rates.

Put some Diesel Kleen in it, drove for 30 minutes, and it quit doing it. Then made a 300 mile trip with no problems.

Next time it pops up, I'll be running the injector test via my EFI Live.

They did not charge me since I had some other work done.

Run a small dose of 2cycle oil in the fuel, about 16oz per tank and it will greatly help the injector. This is a common thing in the LLY's, luckily it has a pretty easy and cheap temp. fix.

Only real fix is a new set of injectors or atleast the one that is fouling on you.

Yeah I wasn't thinking when I put the diesel kleen in. I should have run the test to find the problem injector first.

yeah mine was doin the same thing, 2 stroke oil from Wallymart and problem averted for now (knock on wood), Although every once and awhile it still does do the same thing.

Thanks!!!

Is it ok to run 2 cycle plus power service at the same time?

Mine does the same thing, GM replaced two injerctors saying they were leaking but the knocking remained. It is usually at its worst when going up a small incline at lowers speeds (about 20% throttle). If I remove EDGE unit it goes away. Edge tested the unit ad said it is fine that the edge (even in stock setting) mildly retards the timing. That may cause the audible knock.