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Seeing more ST knock on stock tune versus diablo tune

7K views 31 replies 10 participants last post by  Jake Larsen 
#1 ·
Traveled from Long island to Roanoke, VA a couple of days ago; have the Trinity with 93 tune. Normally see no more than 2 degrees of ST knock on the Diablo tune but after getting some gas down here in Roanoke, I noticed the knock go up to around 3 or 4.00.

Started playing around with the fuel settings on the tune to make it richer; didn't help I think it actually made it worse as the knock went upto around 6 at WOT. Then I reflashed back to the stock tune and started watching the knock. It then actually under a WOT 70+ pull the knock went as high as 10.5!! That freaked me out a little bit given it was the stock tune parameters and I was seeing that kind of knock. Could I have gotten bad gas or something? Note I do not have a catch can yet, so maybe after the long trip I could have gotten some oil in the valves?

Another interesting thing is that after seeing what happened on the stock tune I put the 93 tune back on the vehicle but reset the values; so no fuel adjustment, etc. Did a few hard runs where I could and didn't see any ST knock over 1.5 or 2.0. Seems like it was back to normal but just wondering what might have happened or has anyone else seen this?
 
#2 ·
where abouts in the rpms band did you see the st? Did you let your rig sit for a period of time between tunes? heat from driving around will give you more st. Its possible its the gas but if you saw less st with the diablo tune vs the stock tune with the same gas its not the gas.
 
#3 ·
Quite honestly it happened so fast I wasn't able to notice what rpm I was at. It had shifted down into a lower gear and was climbing rapidly so had to be above 3 or 4,000. I also didn't let it sit between tunes. Maybe the stock tune wasn't completely reset yet after I had played around with the fuel settings on the 93 tune?? I was modifying the 93 tune, started to see the st increase, pulled off into a parking lot, set it back to stock tune then drove off and once I got on the highway after maybe 10 minutes noticed the high st knock happen. Then got it back home and put the 93 tune back on with reset parameters.
 
#4 ·
you will probably see more st if you stomp on it while moving and it downshifts than if you start from a stop. All depends on how low of a gear you can get the tranny to downshift to. For example say it goes into 4th and lugs that gear from a low rpm you will see more st.
 
#5 · (Edited)
The 93 tune isn't good from what I've heard I had horrible st knk also high numbers on 93 run the 91 cai tune I believe that's what most run before they get a Johan or jerseyboy tune they will clear this up also when was the last time you cleaned mani and TB don't quote me but I think this helps also are you running a catch can I'm on phone don't know if you have one


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#6 ·
No, I don't have a catch can yet. That's one if the first things I will be getting when I get back home along with a CAI and Tstat. Have a little over 10,000 miles on it and haven't cleaned the mani or TB. That could be some of the problem since I just came off of a long trip.
 
#15 · (Edited)
I pulled off as a unit the pvc hose,metal tube and the 90 degree rubber fitting where it goes into the manifold and there was NO oil at all in the metal tube or even in either rubber fittings and the jeep has 6200 miles on it. Im just wondering if the 6.4 WK2 PVC unit is a lot better than the 6.1? I did order a BT catch can just to be on the safe side. You have to remember that the 6.4 has a higher compression raito than the 6.1 ( 6.4 10.9 to 6.1 10.3) and like us in CA we only have 91 octane with 1.8% oxy.
 
#19 ·
Ordered my catch can from billet this past week. Will see how long it takes to get here. Vehicle did fine on the trip back. Only saw knock about as high as 3.5 or 4. I've got a little over 10,000 miles on the rig. Would it be a good idea to clean the manifold and throttle body once I go to install the cc?
 
#20 ·
I installed my catch can at like 20 miles and was catching oil with the WK2. I get about a 3/4 full can every oil change around 3-4,000 miles. 21k miles on the rig now.


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#21 ·
Well something definitely weird is happening. As I stated above, I did order the catch can last week but haven't received it yet. Was driving home tonight and just passed someone, rpms around 3 or 4k and started to see consistent st knock around 3, 4 and up to 6.5. Then for the first time i have seen on the Trinity it actually showed 1 degree of lt knock. Guess that the st knock happened long enough on the passing that it showed up in the lt gauge? Can someone help me understand what that might mean? Should I be looking for something on the engine before I get the catch can?

Once I got home, I set the Trinity back to the stock tune parameters; will see how it does tomorrow.
 
#22 ·
Well something definitely weird is happening. As I stated above, I did order the catch can last week but haven't received it yet. Was driving home tonight and just passed someone, rpms around 3 or 4k and started to see consistent st knock around 3, 4 and up to 6.5. Then for the first time i have seen on the Trinity it actually showed 1 degree of lt knock. Guess that the st knock happened long enough on the passing that it showed up in the lt gauge? Can someone help me understand what that might mean? Should I be looking for something on the engine before I get the catch can?

Once I got home, I set the Trinity back to the stock tune parameters; will see how it does tomorrow.
Did it only downshift to 4th?
 
#26 ·
When I saw high st kn I ran a race gas mix to eliminate fuel causing the issue. The race gas mix helped my st kn, so that meant my pump gas wasn't good enough. I would suggest you look into eliminating fuel as the cause first.


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#27 ·
Well catch can is finally coming in this week. Tried new gas with octane boost last night. Still seeing ST knock and now pulling 1 degree on LT knock. It's not the tune as its happening on stock tune as well.

On WOT pulls with speeds 80+ the st knock goes as high as 12. But on the other hand it can blip 1 to 3 st knock just trolling around at low speeds with no load on the engine. I think I must have gotten oil in the intake on my recent long cross state trips for the Holidays. Didn't have these problems before the 10 to 14 hour drive. Any way of knowing if one of the knock sensors might be going bad?
 
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