Cant Figure Out the Knock

[GNBeswick]

Ok, so Ive been chasing this knock ever since I got my engine rebuilt, and its driving me absolutely crazy. The rebuilt engine has everything in my sig and its all new except my fuel pump and fuel pressure regulator. Now the engine has a 9:1 compression ratio, so I expected to not be able to run a ton of boost, but I cant even get to 14lbs without knock. Another issue is if Im in 3rd or 4rth gear and I give it boost, even just a little, it knocks like crazy. Audible knock. I understand that the engine has more load, but it just doesnt seem right to knock from a 45mph roll.
I've been tearing my hair out looking for causes. Ive lowered timing, adjusted the air fuel ratio, reviewed logs of my runs over and over. There's one run where I lowered my timing to 14 degrees in 3rd and it still knocked.
Another small issue I have is when I start the car, it takes a long time to crank. Sometime I have to crank, stop, than crank again. It will always fire on the second try. When it fires though, the car surges at idle a bit and worse in reverse until you put it in drive, than its fine and totally normal. I used to have 42lb injectors and it did not do this, it only started doing it when I changed over to 60s.

Now theres a few things about the cause of the knock that Im not sure about.
One of them is if the AF ratio is around 10:8 consistent, is it at all possible for the cause to be fueling? Even though the AF looks good, would a bad AFPR or fuel pump cause knock? Also, is there anything in the valvetrain that could cause knock? Like lifters not working right, or anything else?

I would greatly appreciate any and all help in solving this knock, I cant get on the car at all because it always knocks and Im just not enjoying it like I should after all the money I poured in it.
Sorry for the essay, and here's a link to all the powerlogger files I have.
Powerloger Runs

 

[Boost231]

i had a similar problem with my new motor. i have about the same motor setup as you. i wouldn't get knock that i could hear with my ears but the powerlogger would show knock. after pulling my hair for about 6 months i said f it. i pulled the factory ecm and put and XFI in the car. problem solved. not sure what it was but it fixed it.

 

[GNRick]

I had a big vacuum leak that I think was causing audible knock. The cap came off the turbo bell where the valve cover pipe was attached to when the car was new. After I fixed the vacuum leaks the knock went away. Are your blms around 128?

 

[Squid4life]

What about fueling? Have you verified your fuel PSI is keeping up with the boost? If you have to crank a few times, maybe your pump is not pumping enough pressure.

 

[TurboBuRick]

Pull the plugs, snap some pics, post them up. Mark the plugs with the cylinder number it came out of.

Rick

 

[GNBeswick]

I had a big vacuum leak that I think was causing audible knock. The cap came off the turbo bell where the valve cover pipe was attached to when the car was new. After I fixed the vacuum leaks the knock went away. Are your blms around 128?

Well the chip I have adjusts fueling according to AF ratio, so the blms will not be 128. The AF ratio stays around 10:8.

What about fueling? Have you verified your fuel PSI is keeping up with the boost? If you have to crank a few times, maybe your pump is not pumping enough pressure.

I tried verifying the fuel pressure increase once, it was real hard to check out the fuel pressure gauge and than the boost, but it seemed a little off. Fuel pressure is set at about 43psi line off and at 14lbs boost it only raised to about 51psi, or at least thats what it looked like to me. Like I said it was hard to read. Thats why I asked if it is all possible the fuel pump or AFPR could be bad if the AF ratio is a fairly steady 10:8, because that seems like a safe AF ratio to me and logically if the AF ratio is fine Id think fueling is fine.

I had been thinking the same thing about the pump as well, sometimes cranks 8-9 times, than I let it rest a second, try cranking again and it fires up after 1-2 cranks. Just find it strange that it did it right after I changed injectors.

Ill try to get some pics of the plugs too

Thanks for the replies guys

 

[TurboV]

Did you upgrade the chip with the new injectors? Alky kit and Translator crossing frequences? (took me 6 months to fix that one. Needed a $15 relay to seperate them.It drove me nuts on a new motor/set-up. Julio makes them, its worth a shot. Car broke up after 14lbs of boost. after that fix, i describe it like stomping on the Lions tail!)

 

[TurboBuRick]

Did you upgrade the chip with the new injectors? Alky kit and Translator crossing frequences? (took me 6 months to fix that one. Needed a $15 relay to seperate them.It drove me nuts on a new motor/set-up. Julio makes them, its worth a shot. Car broke up after 14lbs of boost. after that fix, i describe it like stomping on the Lions tail!)

That would show up in the maf signal on the powerlogger recordings. Good adice but don't think thats the case here.

The no start condition leans more toward a fueling or no spark condition. It would be nice if the problem would just crap out all together so it can be pinpointed.

Rick

 

[ijames]

Remember that O2 sensors, both nb and wb, get fooled by misfires and read rich. You really need to verify the fuel pump at full pressure. First just rig up a tire pump with gauge to the fuel pressure regulator and make sure that with the engine off you get 1 psi per 1 psi all the way up to at least 70 psi fuel pressure. If that works, break the return line connection at the front of the engine down at the frame crossmember and use the tire pump to get 70 psi fuel pressure and time how long it takes to deliver 1 gallon. Should be about a minute. With the bad Walbros people have run into over the last year that is definitely suspect.

Oh, from personal experience I got C16 to knock from being too rich but I had to go well richer than 9.5:1 .

 

[Nasty Wendy]

Does it knock like that with race fuel?

 

[BRAD_PADGETT]

Check out the response by suicide six. List of all known knock causes. Mine was number 32. Good luck- Brad

http://www.turbobuick.com/forums/general-turbo-buick-tech/188574-knock-knock.html

 

[GNBeswick]

Injectors and chip were both installed together. Im currently not using my alky system because I would like to have the knock solved first, so I dont think its crossing signals. Car doesnt break up either, at least I dont think it does, if my understanding of the term "breaking up" is correct ( surging, sputter, loss of power)

I will try that test with a bike pump when I get a chance.
I do not have aces to race fuel, so I am not sure whether it would knock or not.

Here are pictures of all my spark plugs, they are all numbered except for the #1 cylinder. I noticed that the two rear plugs (5 and 6) have much more soot on the rim, 6 being the darkest of all. Plug #4 also seemed to be greasy or oily around the rim.

 

[GNBeswick]

 

[jdpolzin]

How does the knock come on??? Is it immediately high or does it gradually works it's way up? If it's immediate, it's probably false. I agree a no start issue would suspect fueling or spark problems BUT, dont let that sway your mind in figuring out the knock. It could be two different problems. What are your TPS and IAC counts? Have you attempted to swap the MAF sensor just to be sure its not that? Sometimes simple things can cause these problems. Also, are you sure the coil pack and module are good? Do you have spares to test these parts out? Start simple.

 

[jdpolzin]

Also, do you have the jack in the trunk? Sounds dumb but a buddy had a similar issue as you do removed the jack. Knock went away so he must not have had the jack in tight and the knock sensor read a harmonic noise through the entire car. Sounds far out there but if anything is loose, the knock sensor may pick it up.

 

[GNBeswick]

The knock jumps most of the time, and recently Ive been able to actually hear the knock so I know its real. If you check out the powerlogger folder I posted you can see everything thats going on. I unfortunately dont have have spares of anything so I cant swap out. The only thing that Im pretty much 100% positive on being good is my coil module because its brand new.

 

[jdpolzin]

I'm not able to open the Log Files but for some odd reason, I have a fealing it's either the injectors/chip or the MAF sensor. Who did the chip? How old is it? Are the injectors new? Or at least flow tested?

 

[jdpolzin]

Also, do you have a Power Plate? If so, are you sure it matches your plenum? #6 is defintately running richer than #5 by the looks of the pictures. I'm wondering if you have a Air dispersement problem in the intake?

 

[GNBeswick]

Hmm....is it the zip file that isnt working or the actual powerlogger files. Is anyone else having trouble?
Chip is an Eric Marshall TurboTweak chip. Bought it the same time I bought the injectors, about 2 months ago. Injectors were purchased from Full Throttle, so Im guessing they were not flow tested.

 

[jdpolzin]

I know you have made some adjustments to Eric's tune, did you have any problems before these adjustments?

BTW, I just cant open the actuall files out of the folder but I'm also not computer savy and my computer is anchent so that may bemy problem.