General 1G phantom knock cured

[Talonman]

another place to check is your fuel pressure soleniod going bad and not increasing fuel pressure with boost thus leaning the fuel way out causing knock. I guess its not phantom but real knock since your not getting enough fuel. You can just bypass the fule pressure soleniod by connecting the 2 vaccum hoses running to and from it together or replace both with one line from intake mani to the fuel pressure regulator on the end of the rail.

 

[2.4 turbo Hyped]

It eliminates phantom knock below a certain rpm level. Information on it is widely available by doing a search.

 

[markgholland]

It eliminates phantom knock below a certain rpm level. Information on it is widely available by doing a search.

Did you read anything I said or did you just wanted to type, "do a search." I understand what the chip does; that is not what I was saying. I asked Kyle to comment on PK if he wished to do so.

I said it before, but I'll say it again for those who missed it the first time; there is a reason the PK is present, so why not fix it at the route of the problem(s) rather than go around it? It could be a valuable tool, as proved in this thread, that you may have other problems.
~Mark

 

[2.4 turbo Hyped]

another place to check is your fuel pressure soleniod going bad and not increasing fuel pressure with boost thus leaning the fuel way out causing knock. I guess its not phantom but real knock since your not getting enough fuel. You can just bypass the fule pressure soleniod by connecting the 2 vaccum hoses running to and from it together or replace both with one line from intake mani to the fuel pressure regulator on the end of the rail.

To my understanding the purpose of the fuel pressure solenoid is to increase fuel pressure while the engine is hot during a startup. This has nothing to do with while you are driving the car. Mine is removed.

 

[2.4 turbo Hyped]

Did you read anything I said or did you just wanted to type, "do a search." I understand what the chip does; that is not what I was saying. I asked Kyle to comment on PK if he wished to do so.

I said it before, but I'll say it again for those who missed it the first time; there is a reason the PK is present, so why not fix it at the route of the problem(s) rather than go around it? It could be a valuable tool, as proved in this thread, that you may have other problems.
~Mark

Its sad we could go on for days arguing this point but alls I can tell you is this: I have replaced every single mechanical part on my vehicle and my phantom knock is still there. Its only a part throttle knock at low rpms. Never knocks when the rpm is higher than 3 grand. Problem is once it starts it wont go away until the accelerator is let off and depressed again. Im sure many of the other "victims" of this issue will tell you the exact same thing I have. You are right there is something wrong with the vehicle it has phantom knock.

 

[Coldandafraid]

Its sad we could go on for days arguing this point but alls I can tell you is this: I have replaced every single mechanical part on my vehicle and my phantom knock is still there. Its only a part throttle knock at low rpms. Never knocks when the rpm is higher than 3 grand. Problem is once it starts it wont go away until the accelerator is let off and depressed again. Im sure many of the other "victims" of this issue will tell you the exact same thing I have. You are right there is something wrong with the vehicle it has phantom knock.

I get the EXACT same thing.

 

[2.4 turbo Hyped]

I get the EXACT same thing.

See? Many people have this issue its not just me. Heck visit the phantom knock board at yahoo. Im tempted to just put a 560k resistor in place of the knock sensor and blow the motor and junk the car all together. This is how frustrating this problem is. Even after replacing an entire engine and 3 transmissions and related parts the phantom knock is still there. Go figure.

 

[pneumo]

... Its only a part throttle knock at low rpms. Never knocks when the rpm is higher than 3 grand. Problem is once it starts it wont go away until the accelerator is let off and depressed again.

Here's a little tidbit of info I picked up from the DSM-ECU list, and it's one part of the PK code. Whenever you get knock and the throttle is above a certain setting the ECU will continue to pull timing, even if there isn't any more knock detected. A good example is when you do a WOT pull and see knock spike up to, lets say 15 counts, then the knock gradually tapers down without any other increases. What is really happening is the ECU heard some knock at first, the ECU pulled timing, and it was slow to give the timing back even tho there wasn't any more knock.

The rate at which the knock is reduced is known as knock decay. At low throttle settings the decay rate is quick, so the timing comes back quickly. At WOT the decay rate is very slow. When the throttle is closed knock is reset to 0. BTW did you know when the logger shows knock it's really showing the difference between the maximun timing possible for the given conditions (airflow, rpm, temps, etc.) and the actual timing? Loggers don't read any part of the knock sensor input.
So the PK code that was mentioned contains features that allow the knock readings to decay more quickly. It also lets the ECU ignore knock under light load conditions. That way a car is much less likely to pull timing from knock induced at throttle tip in ( which is a major cause of knock on a modded car) and if there is some knock, it decays quickly, which shows up on the logger as a rapid decrease in "knock".

And in case anyone thinks that ignoring knock is a bad idea under ANY curcumstances should know that the ultra safe factory code already ignores some frequencies of knock under certain conditions, such as light load driving.

 

[Coldandafraid]

ok... never knew that... however, like he said conveniently in the part that you quoted... the knock doesnt go away until the throttle is completely let off, and then opened again. So... no "decay"

But, at WOT, it does come and go.

 

[2.4 turbo Hyped]

Thank you for clarifying that pneumo. Its nice to see an educated answer. I wasnt exactly sure what the code does but now I understand what you are saying fully.

 

[98spydert]

I don't have any answer for PK but I will add this as maybe it will help someone track down an answer.

I switched to the blow thru GM MAF/ MAFT set up and had horrible tip-in knock and wierd spells of 42 ct PK. I battled it for about a month with no luck. No matter how rich I went for the mid range air flow, it either got worse or stayed the same. A few weeks ago I swapped in a ported e3 16G and tubular 2.5" o2 housing and ALL of the tip-in and PK knock is long gone. Only thing I really did concerning around town driving(where I had all my knock problems) is increase spool up time (from a T-25 to the evo 16G) and reduce back pressure with the ported turbo and tublular O2 housing.

Like I said, i don't know how or why it's gone, just thought it was intersting.

Edit: BTW, I had the EXACT same problems 2.4 turbo hyped talked about in post #30

 

[121xgigawatts]

Its sad we could go on for days arguing this point but alls I can tell you is this: I have replaced every single mechanical part on my vehicle and my phantom knock is still there. Its only a part throttle knock at low rpms. Never knocks when the rpm is higher than 3 grand. Problem is once it starts it wont go away until the accelerator is let off and depressed again. Im sure many of the other "victims" of this issue will tell you the exact same thing I have. You are right there is something wrong with the vehicle it has phantom knock.

After reading your post I tried letting off the accelerator to see if my knock count went to 0 and wot was normal. You can add another person to you list becasue mine does the exact same thing. Have you found any other solutions other then the chip mod? Would replacing the ecu do the trick? I understand your frustration with pk, I feel the same way.

 

[2.4 turbo Hyped]

After reading your post I tried letting off the accelerator to see if my knock count went to 0 and wot was normal. You can add another person to you list becasue mine does the exact same thing. Have you found any other solutions other then the chip mod? Would replacing the ecu do the trick? I understand your frustration with pk, I feel the same way.

Rumor has it replacing the wire from the alternator to the underhood fuse box and from the battery to the alternator fuse sometimes works. Use an 8 guage wire. I will be trying this, this weekend (money willing). I'm gonna just end up buying a chip burner and learning how to burn the code. Seems to be a good investment.

 

[pneumo]

I read that thread on DSMTalk, too. A guy rewired his alt and his car ran better. I can only guess how bad his wiring was for that to help. I can see how some older cars in the snowbelt could benefit from fresh wires since the alt. wire runs down below the radiator where it's more likely to pick up moisture and corrosive road grime. I found some corrosion inside the wiring of my A/C fan when I swapped it onto a slim fan, so it can happen.

I just had an idea; if letting off the throttle resets knock to zero, why not run a pushbutton switch in the TPS wire? That way if you get high knock counts you could hit the switch quickly to reset the knock count without letting off the throttle. This is just a preliminary idea, I haven't thought it through yet, this idea might actually sux, but who knows?

 

[2.4 turbo Hyped]

I read that thread on DSMTalk, too. A guy rewired his alt and his car ran better. I can only guess how bad his wiring was for that to help. I can see how some older cars in the snowbelt could benefit from fresh wires since the alt. wire runs down below the radiator where it's more likely to pick up moisture and corrosive road grime. I found some corrosion inside the wiring of my A/C fan when I swapped it onto a slim fan, so it can happen.

I just had an idea; if letting off the throttle resets knock to zero, why not run a pushbutton switch in the TPS wire? That way if you get high knock counts you could hit the switch quickly to reset the knock count without letting off the throttle. This is just a preliminary idea, I haven't thought it through yet, this idea might actually sux, but who knows?

Haha! because when you press that switch your rpms will drop to 1500. I tried that already.