zapata41

So I was running the truck and noticed that while scanning it the knock sensor is retarding the timing 8deg in the upper rpm while WOT giving me a timing of 6deg btdc. Could the valve train be causing the knock sensor to think it is knocking. You can really really feel the retard when the sensor starts killing the timing. i have some scan files and tune files if anyone cares to take a look at them.

Thanks

Tim

dewmanshu

iTrader: (4)

Shove some high octane potent fuel in there and see if it keeps doing it. kr at WOT is pretty believable if it is between shifts and converter lock ups.

zapata41

it was around 3000-5000 rpm kr in full force at 8deg. would some octane boost help with some 91 fuel. i always run 91 as it is. it just seemed a little odd that it can only run 6deg of timing

Thanks

Tim

dewmanshu

iTrader: (4)

it is odd. I am just curious if the higher octane "calms" the kr reading. You can't hear it? no pinging or crackling, even faint? You using hpt or efi? Attach your tune regardless. Use the attachment feature on the reply panel.

lady3bglover

iTrader: (3)

I tried the high octane when my knock sensors started acting up and it didn't help. Fortunately my truck was still under warranty, and the sensors were replaced. Check and see if there was a recall.

Lisa

zapata41

i would love to attach the file but it is larger than the 100k file size. i am using JET DST tuner, soon to be hptuner. the knock sensors are new, maybe 5k miles on them, i replaced them when i did cam swap. i can email the tune to someone if they want to look at it. dont know ho else to get the tune online.
as far as pinging or crackling, never noticed anything. i do notice that the power aint what i would expect from the motor. although dyno numbers werent bad, i was just hoping for better.
Thanks

Tim

dewmanshu

iTrader: (4)

Yeah, that is the deal sometimes...rarely though. Even so, if you are having HUGE kr on a scanner and you don't hear it and 101 or 110 octane fuel doesn't phase the amount of kr (given also you tune isn't bunk) then there is mechanical problem of some sorts.

The power loss is obvious, you are losing 8* of timing.

If the knock sensors weren't seated well, or the rubber around them was cracked or connection is just good enough to not throw a code but bad enough to cause havoc (doubt it)you could have issues. If you have vcm controls, try a case learn and cylinder balance. Probably won't cure anything, but since you did a cam swap I'd be looking for the culprit to be around that cam swap (guessing you didn't have kr issues b4 the cam swap). Walk thru every step of your cam swap and make sure you're not leaving anything out. Knock sensors the right part numbers? (I don't think that matters though)

I don't think I can look at JET DST stuff, what is the extension of the file? Email it to me anyway, I can at least host it up for you so others can look at it. dewmanshu@deweygibson.com

WS6Truck

Just curious, what's your AFR reading when you get the KR?

zapata41

i dont know about having the problem before the cam swap as i did it just after buying it. i dont know the afr reading as i dont have a wb yet. when i did the cam swap i broke a knock sensor so i replaced them both with new ones, i believe the plastic on the wire connector did break when removing them but it still made a positive contact, maybe it is wiggling loose a little under high rpm high vibration. ok well i did adjust tune to scale kr @ .5 so cutting the values in have. going to the snow in a minute so i will have a few long hill pulls to listen for knock.

Thanks

dewmanshu

iTrader: (4)

Here's your Links...

rev 3.5

rev 4