LLY: Help: LLY seems to be pinging / knocking...

[Triple L]

Hay guys, So just recently my truck started doing a pinging / knocking right around 1700-2000 rpm only while under load, 40-60% throttle, No visable smoke and runs good in the power band everywhere else... When it first started i had it on the economy tune on the PPE hot+2... Thought it wasnt getting enough fuel or something wasnt right so I bumped it up to level 3... Ran good for a while, but I didnt drive it much after i turned it up... Today i started driving it again and its still doing it... So i set it back to completely stock, and it still does it... Is this bad fuel, timing not right, or what could it be...

I took a quick video today, if you listen around the 10 second mark you can kinda hear it...
http://www.youtube.com/watch?v=QRyO5_VANKk

Any suggestions would be appreciated!

 

[Diesel Pilot]

I would guess so lower than adequate fuel. I notice mine has a bit of a rattle sometimes in the winter like you descibed. Put in some additive or B20 and you should notice a difference.

 

[Redbowties88]

cold be the injector harness connection at injector #7

 

[Krazykid]

cold be the injector harness connection at injector #7

What should you look for at this location?

 

[Redbowties88]

What should you look for at this location?

you cant tell visually...just have to pull the connector ice pick it and see if it solves the problem..

#2 injector harness is also troublesome on LLY but usually that will cause the shutdown of that whole bank and the truck will barely run. also check the wires that run in a raceway over the alternator for chafing

 

[Triple L]

Thanks for the suggestions, Im running sunoco gold diesel which is pretty much the best stuff we can buy in canada... 3 cents more per liter then the regualar stuff...

When i use the diagnostics on the PPE tuner all the injectors seem to be firing property and the fuel pressure is good... If there was a problem in the injector harness it should show up when im scrolling throw right?

 

[Redbowties88]

not necessarily....the vibrations at that particular rpm cold be causing the connection to be broken...can you scan with ppe and rev the engine to the range where it knocks and try again?

 

[Triple L]

Thanks for the advice guys, Im gonna have to get to that soon.... The problem is it only does it under a slight load and i've drove around with the tuner in my hand and looked thru everything thing and its showing all the injectors firing properly...

Yesterday I Put it back up to level 3 on the PPE as it seemed to be running alright again... And same crap, Banging and running like crap almost instantly again... So I took the timing and rpm increase out of it, reduced it a bit, but its still doing it quite a bit... Seems it only wants to run on stock, and even then it still does it everynow and then but nothing that im too too worried about... I dont think putting a 1/2 bottle of conditioner in for every 1/4 tank is very good as a continuial basis anyways...

Any other insight?