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knock problems...logs included... Update 11-11-10

evo8ya

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Joined
Jul 7, 2006
Messages
351
Location
PA/MD
Where is your base timing set at?
 

Quoting Jason G.:
Maybe try some race gas and see if that clears it up.



this is exactly what im thinking. maybe your gas station has stale gas? throw some 110 octane in there for a tank and see if your logs change. unles you have a watermeth kit?
 

BoostedAWD91

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Mar 1, 2007
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Danville,Pa
it cant be the gas, i use the exact same gas from the same station and never had a problem
 

SleepinGVR4

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Feb 12, 2003
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Location
Danville, Pennsylvania
I was heading to class today and while I was on the highway my car just started sputtering/vibrating like it was miss firing. It only did it when I got into boost. And I couldn't see any smoke from my tailpipe. This has actually happened before and I swapped CAS and the problem went away. But obviously that wasn't the problem.

It usually clears up by itself and goes away after a little while. /ubbthreads/images/graemlins/dunno.gif The WB was progressively getting richer like it should under boost. The plugs are new BR-7ES that Hill and I put on the other weekend. The coil pack was just replaced at the same time. The wires are newer NGK wires. I even swapped a spare transistor pack that I had in the car, didn't help.
 

SleepinGVR4

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Danville, Pennsylvania
1941Galant and I ended up swapping ECU's, doing a compression test, another boost leak test, and took the valve cover off to see if a rocker arm popped off.

Swapping ECU's didn't help anything.

Boost leak test showed no leaks.

All the rocker arms are where the are supposed to be.

The compression test was interesting. Last time I did one the number four cylinder was reading low. But this time All the cylinders were around 180-170 except the number two cylinder which I think Hill said was 160psi. Its not horrible but if I remember right its out of the acceptable range of compression. So we put a cap full of oil down the spark plug hole and cranked the car over. Nothing changed. Hill mentioned that one of the valves may not be closing fully due to carbon build up on the valve. Which is definitely possible due to my car running extremely rich at tip in.

So we decided to retard the timing to be on the safe side and keep the knock down. Made a world of difference. The highest knock I've seen now is 10 counts, but usually I only see 2 or 3 counts which I'm almost positive is phantom knock.

Hill and I have come to the conclusion that is has to be a fuel problem. Hill swears my brand new Walbro is much quieter than it should be. Its like the fuel pump voltage jumps up and down whenever it feels like it. Last night I did a 2nd gear pull and the car pulled hard and had zero knock but a huge could of black smoke came out which I figured was because it was running rich and the fuel pump voltage decided to be normal at that certain point in time. I can't figure out why that would be, with the re-wire kit the fuel pump is getting power directly from the battery which is in my trunk a whole 3 feet away from the sending unit.

My battery is only grounded in the trunk on one of the strut mounting bolts. I know I've read before that people recommend running another ground back up to the engine bay. But I didn't really think this was necessary.

Thoughts please.
 

Jason G.

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Oct 7, 2003
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3,279
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Anderson, SC
160 isn't out of the acceptable range and is close to spec.
There is a bit of deviation between cylinders but it's not close to being critical.

Did you happen to try a little race gas to see if the knock went away?
 

belize1334

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Nov 18, 2003
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3,316
Location
Bozeman, MT
You could have one clogged injector and then the others running overly rich giving you a good average value. How are you checking your AFR?
 

Recheck the gaps on your plugs you may need to close the gap down a bit to control the sputtering under high boost. I am experiencing similar issues as you are right now and I just installed a brand new knock sensor and at light or partial throttle I am seeing 2-3 counts sometimes more. Even at idle all of a sudden 2-3 counts are on my logger. Driving home last night not even driving hard just under cruise control I look at my logger and see 24 counts wtf? Like you I emailed Jeff who confirmed that my chip has the PK code so I am lost too. I may try retarding the cas like you did and see if that works also its really weird that my stock boost gauge that Jeff converted to show knock sum does not indicate knock when my logger does doesn't light up and it does work because under heavy boost when it does knock it lights up.Whats the torque spec for the knock sensor anyway.I spoke to a well known dsm tuner on tuners and he recommends going with a reburned chip with a evoviii timing maps. He thinks the 1g/galantvr4 maps are way too aggressive when these motors are coming into boost and 100%VE I dont know wth?
 

Do you have the stock lifters or the revised 3g lifters and what weight oil are you running? Stock intercooler or upgraded intercooler...
 
Last edited by a moderator:

Nate

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Feb 23, 2001
Messages
944
Location
Worcester, Pa
Pull the fuel pump out of the tank, remove the filter sock from the bottom of it, replace in tank, and go for a quick test drive. Preferably do this after you've been driving around a bit, so that the pump has had to run for a while and then get warm.

I had a problem years ago where the car would run fine for a while, and then go lean under load, no matter what I changed. Eventually, after months of messing with it, I figured out that the filter sock on the bottom of the pump was clogged, causing the pump to starve for fuel, causing a lean condition. Took about 8 months of diagnostics to figure that one out.

Good luck.
 

SleepinGVR4

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Danville, Pennsylvania
Quoting belize1334:
You could have one clogged injector and then the others running overly rich giving you a good average value. How are you checking your AFR?



I just had the injectors flow tested and cleaned 2 months ago. And I have a AEM wideband.
 

SleepinGVR4

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Feb 12, 2003
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Danville, Pennsylvania
Quoting Blown1:
Recheck the gaps on your plugs you may need to close the gap down a bit to control the sputtering under high boost. I am experiencing similar issues as you are right now and I just installed a brand new knock sensor and at light or partial throttle I am seeing 2-3 counts sometimes more. Even at idle all of a sudden 2-3 counts are on my logger. Driving home last night not even driving hard just under cruise control I look at my logger and see 24 counts wtf? Like you I emailed Jeff who confirmed that my chip has the PK code so I am lost too. I may try retarding the cas like you did and see if that works also its really weird that my stock boost gauge that Jeff converted to show knock sum does not indicate knock when my logger does doesn't light up and it does work because under heavy boost when it does knock it lights up.Whats the torque spec for the knock sensor anyway.I spoke to a well known dsm tuner on tuners and he recommends going with a reburned chip with a evoviii timing maps. He thinks the 1g/galantvr4 maps are way too aggressive when these motors are coming into boost and 100%VE I dont know wth?



I just tighten my knock sensor down a little bit to where I don't think it will back out. Thats it. Also I've had my LEDS do the same thing. I have my wideband wired into my EGR wire on the ecu harness so I can log it with the logger. What I've come to believe is the logger sees all knock, phantom or not. The LEDS, on the other hand, display anything not eliminated by the phantom knock code. Granted this is just what I believe I have NOT asked Jeff if this is true or not.

Another thing I'm going to try but haven't yet, is that someone on another board asked if my intake manifold had any carbon build up in it. I told him there was when I put it on, I tried to clean it the best I could but I don't think it was good enough. So I'm going to take it to my machine shop and have him soak it in his parts cleaner. Something you might want to try.

Also I'm going to take my intercooler off and clean that out.

Retarding my timing did help but now for some reason, and this only happens sometimes, when i get into boost the car starts to sputter and I can feel the whole vibration through the car. It also has become real hard to start sometimes. I'm going to check my plug wires again and a couple other things.
 

SleepinGVR4

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Feb 12, 2003
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Danville, Pennsylvania
Quoting Blown1:
Do you have the stock lifters or the revised 3g lifters and what weight oil are you running? Stock intercooler or upgraded intercooler...



I have the 3rd gen revised lifters in my car. And right now I'm running 20w-50 but I'm doing an oil change today and switching to 10w30 for the winter. I have a custom ETS FMIC.
 

SleepinGVR4

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Feb 12, 2003
Messages
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Location
Danville, Pennsylvania
Quoting Nate:
Pull the fuel pump out of the tank, remove the filter sock from the bottom of it, replace in tank, and go for a quick test drive. Preferably do this after you've been driving around a bit, so that the pump has had to run for a while and then get warm.

I had a problem years ago where the car would run fine for a while, and then go lean under load, no matter what I changed. Eventually, after months of messing with it, I figured out that the filter sock on the bottom of the pump was clogged, causing the pump to starve for fuel, causing a lean condition. Took about 8 months of diagnostics to figure that one out.

Good luck.



Thanks Nate but I figure out the lean condition while cruising. I thought exactly what you did. I changed pumps got a new fuel sock. Eventually I figured out that the stock fuel line from the tank to the filter was partially clogged some how. So I replaced it with braided line from the sending unit to the filter and that fixed that problem. Now if I can only figure out the other problems. /ubbthreads/images/graemlins/banghead.gif
 
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Quoting SleepinGVR4:
Quoting Blown1:
Do you have the stock lifters or the revised 3g lifters and what weight oil are you running? Stock intercooler or upgraded intercooler...



I have the 3rd gen revised lifters in my car. And right now I'm running 20w-50 but I'm doing an oil change today and switching to 10w30 for the winter. I have a custom ETS FMIC.



Ok looks like you have all the bases covered except for the oil I just did an oil change and switched to 10w-30 myself. Stock lifters are a lot more quiet now only problem is I cant find the Valvoline VR1 racing oil in 10w-30 so I may have to order some brad penn online both are highly rated.Let me know how it works out for you looks like we have similar issues I think a part of my problem is running too much boost on the stock intercooler I don't have a fuel problem as far as I can tell. I need to get a new front crash bar though it looks rusty and rotted as hell before I have my friend install my shiny new intercooler and pipes. Keep me posted if you get things figured out.Will add new 3g lifters and some other stuff if and when I decide to rebuild the motor....
 

Launch

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Joined
Aug 17, 2006
Messages
350
Location
Texas
+1 on brad penn. Got to watch it in action and being worked pretty hard on a daily basis. My new motor has been fed nothing but it.
 
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