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Help with knock. (Making progress)

James

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Ok. This has been an on going problem for a while. For SOMR reason MMCD logger is showing 0-46 counts of knock depending on load. This can be at idle giving it a free rev or under normal cruising condition also during WOT pulls. As it appears on the logger... RPMs go up->knock comes on->timing is cut back to 7-10.

I knew the lifters were super loud. I replaced the knock sensor. I did all of the cheap tricks to get rid of phantom knock. Today I replaced the lifters and it sounds much better. Also driving it feel amazing again. But I hooked up the logger only to see the same things as before. Only difference I see is the timing isn't being set back as much as before (probably why it feels better). During two logs of WOT pulls the most it was set back was 18-22 degrees at 45 counts of knock.

Now I know I can buy a EPROM ECU and chip it to ignore the knock but I don't want to patch the problem I want to fix it.

2g MAF/550cc injectors/SAFC2.

The SAFC is set to +6% low throttle/+9% high throttle.

Low fuel trim- 96
Medium fuel trim-97
High fuel trim-85

Now I know that the high fuel trim is a little low but when I adjusted the SAFC to add more fuel at high throttle and it started breaking up. Thats where I'm at right now.

If you need any other values let me know!
 
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5OF2k

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Couple things to look into also. Check your knock sensor for gooey stuff inside, right where the plug connects. If its in there, you need a new sensor. Id also recommend pulling the knock sensor and wrapping the threads in teflon tape, a couple times. That will insulate the sensor and help determine if the knock is something factual or simply a faulty sensor.

Next, get rid of the SAFC. Its funny how you mention noth "patching" but fixing, yet are using a device thats designed to FOOL the ECU from seeing the true volume of air the car is seeing pass its vital sensors. SAFCs are a bust in my opinion, and I dare say youre far better off using a GM MAF/Trans than you are using an SAFC.

Hope that helps!

-Jake
 

turbowop

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Adding fuel won't bring up your hi fuel trim. You need to take out fuel. The trim is saying that the ECU is trying to remove fuel. Adding more will only exacerbate that.

The SAFC works fine for what he's trying to do. It's only a matter of fine tuning since he's using a 2gMaf/550 combo. For anything needing large adjustments, there are much better alternatives to the SAFC.
 
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James

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Everyone can argue SAFC good or bad and nobody will ever win that argument. It's a near stock setup and the SAFC. Does what I need it to.

I mentioned already doing the cheap tricks to nullify what te sensor hear, and I also mentioned getting a new knock sensor.

WOP- good point I guess I hada stupid moment, that's probably why it was breaking up
 

5OF2k

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Cool cool, didnt mean to offend if thats the case. Im simply offering suggestions that i've used myself, as well as many many many many others over the years, that work. /ubbthreads/images/graemlins/dunno.gif

-Jake
 

James

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None taken. My ex dropped off my little one so I can't do to much more. I make the correct adjustments to the Safc in the morning but I don't think that's going to fix my issue.
 

matt92vr4

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45 counts of knock is ridiculous especially in neutral with no load. It can't be real. The only time I've seen this was with a very poorly built engine with the wrong piston sizes. What's the history of the engine?
 

James

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History is unknown. Assumed to be swapped out of a 92 talon TSI awd. I know its not real knock, as I'm pretty sure a constant 45 counts of knock on 93oct and 10psi first off is not likely and if it did happen would problem grenade the motor a long time ago.

But I can't figure out what's causing it
 

James

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Well it's relative to load/RPMs it seems.

I was at 2500 in third gear and floored it for a log. As soon as I hit the gas I see...
45 counts of knock/-2 timing
I held this till 2800 where I let off for a second and got back on it to see...
30 counts of knock/+10 timing
Repeat process at 3200 and see
20 counts of knock/+20 timing
Repeat at 3500 to see
0 knock/+40 timing


Does that mean anything to anyone? Or help at all?
 

James

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Still looking for assistance here. Haven't figure out how to post a full log. So here's so key points I took a photo of.


This is just running through the gears. You see RPM/FTO2/KNOCK/TIME ADVANCE


This one is during a third gear pull starting around 3k

 

James

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Pink: FTO2
RED: RPM
gray: knock
Purple: timing advance
 

James

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Nothing eh?
 

James

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But look at the knock line across the graph. Some spots it hits a steady 45 for 5-10 seconds lol.
 

matt92vr4

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Don't know if this will help but... When we use to build new engines for an aem setup our first dyno runs would be at 0 boost. This would give us the engines natural noise counts and then we would set the actual knock parameters from there. To get 0 boost to redline we would have to run the air from the turbo to atmosphere while at the same time run pressure to open the wastegate so the turbo didn't spin crazy. Anyways every engine has a different natural noise that is not knock. Perhaps your engine is very noisy at the lower rpms.

I would try to clamp your wastegate open and run with 0 or close to 0 boost to see if you still get the knock counts. Have you tried to roll back timing or add race gas to see if it will go away?
 
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turbowop

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If you're seeing knock while just cruising at low rpm/tps, especially maxed out counts, then you're getting phantom knock. The only way to control this is with a custom chip or ECMlink so you can change the parameters at which the ECU ignores the knock sensor.
 
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James

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In going to roll back the timing tomorrow because as you can see in another thread its set at +10 at idle. But I would think if this was the problem that it would cause knock all the time, as you can see in the WOT pull I can keep the knock down.


Wop- my next question was going to be... Is there some forms of phantom knock that are just impossible to make away? Where the chip is the only option? I wouldn't mind doing that but its just going to be a lot all at once. Needed to find a god EPROM ECU and getting it socketed the. Buying the chip. Sometimes I wish i would have just done that months ago instead of buying the SAFC
 

iceman69510

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Not in a location I can verify this at the moment, but isn't base timing +5*?
 

ktmrider

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Quoting James:
In going to roll back the timing tomorrow because as you can see in another thread its set at +10 at idle. But I would think if this was the problem that it would cause knock all the time, as you can see in the WOT pull I can keep the knock down.


Wop- my next question was going to be... Is there some forms of phantom knock that are just impossible to make away? Where the chip is the only option? I wouldn't mind doing that but its just going to be a lot all at once. Needed to find a god EPROM ECU and getting it socketed the. Buying the chip. Sometimes I wish i would have just done that months ago instead of buying the SAFC

Your last sentence is what whop and others have been trying to get across since day 1.

Yes base timing is +5 degrees with DIAG port grounded.
SAFC only tweaks airflow, timing is not affected.
Timing on TEL/GVR4 4G63T engines is already agressive stock.
Using SAFC only some set base timing to +3 degrees.
1g versions suffer from Phantom Knock issues.
1g MAF units run out of metering capability around 15psi ( healthly intake system ie no leaks ).

You fell trap to common DSM/TEL/GVR4 suggestions. Do it right, do it once, beware the internet forum advice moving forward.
 

matt92vr4

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If I remember correctly from my shop days, the SAFC does in fact increase timing indirectly at WOT. It fools the ECM into thinking less air is flowing and therefore the ECM will use the timing map for that particular false airflow amount (which is probably more timing). So, if your base timing is advanced and the SAFC is fooling the ECM to use a higher timing map, then this could produce your issue.

Still, 45 counts is ridiculous at 2500rpm. How much boost are you running? Let us know what happens when you set the timing back.
 
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