BAD!! Knock LOW RPM's

[AWDGrayBird]

Ok i just got my car running a week ago. I put in 6bolt with 95 pistons with 5k on the rebuild. When i pulled the motor it had never knocked in my other car. Well i put it in with a New Knock sensor,o2 sensor,GM MAFT, FMIC,Tial BOV,Walbro 255hp,780cc inj,and a Keydiver chip to Adjust for the 780cc inj i got enhanced closed loop,no a/c,Eliminate Fuel Cut, Octane resest, etc... well i got it running and it ran fine for about 20 minutes then it started to knock below 3.5k only if you got on it hard. If i stay on it it would just keep knocking but if i let off and floored it again it wouldn't knock if it was still above 3.5k when you got back on it. It would jump to 43 counts like nothing when it knocked and so i went home and let it cool and checked my plugs they where black this it with less than 20miles on them. So i leaned it out a little and it knocked worse so i put the settings all back to 0 and after i got the clutch broke in i layed in to it on a 3rd gear pull and at about 5k it start missfiring and black smoke poured out the tail pipe went home and leaned it out the WOT and and added to idle and mid and went again still knocked like a MOFO then i got it up above 3.5k and 15 psi it ran beautiful but the egt said 1300 WOT 7k no knock no misfire. SO i took it home and no matter what richen or lean it out it knocked the same below 3.5k.I tried the stock ecu,New Plugs,Wires,Knock and o2 sensors and it still knocks but now my fuel low lights on and it knock all the way till 5.5k, All FT are between 95-105% o2 between 90-110%, I am on my 6th set of plugs in 100 miles oh and i am getting 8mpg.

Thank you
Dustin

 

[burldude]

check you fuel pressure then check you alternator . Then I would consider internals .

 

[kpt4321]

You're getting 8 miles per gallon, but your fuel trims are all perfect? Something is wrong with that.

 

[AWDGrayBird]

You guys think running 0w-40 Mobil 1 for cold starts is any part of the problem. i usally run 10w-40 Valvoline Durablend.

 

[BoostinAWD]

Yea your running a walbro 255 high pressure and 780cc injectors with no regulator. Definetely running way too rich which is gonna possibly result in knock just about everywhere.

Get a damn regulator already.

 

[BoostinAWD]

Oh yea check your timing. It might be advanced way to far.
Sounds like its phantom though, might was well try changing your oil to something a little thicker (if its ticking loudly) make sure nothings vibrating against the motor.

 

[talontsiboy24]

0W-40 actually stopped my motor from knocking at cold starts compared to 15w-50 i was using before man in winter i start it and get knock for 2 or so minutes which is very bad so now im using 0w-40 for winter only then i will switch back.

 

[z24frank]

whats considered too much knock?

 

[johnmarines]

from what I have read.... if your tuning aggressive... over 3* if tuning conservitivly over 1*.

 

[JayRolla]

Sit in neutral and rev the motor watching the knock sum. If you get lots of knock just free revving than Im guessing its Phantom Knock(PK) which is audible noise picked up by the sensor that is not knock. Could be too tight or loose of a sensor, valve tick, or even something simple like exhaust rubbing on the oil pan or somewhere. Even poly motor mounts have caused PK.

 

[the_mork]

I would also suggest trying some race gas, with a low fuel light on now is the perfect time. Put about 4 gallons in and see if your knock goes away. If not then it is almost certainly PK. Do you have a wideband? If so what AFRs are you running? What does your timing curve look like? Care to post a log?

 

[dsmnthamakin]

i have the same issue in my 1g gsx where at idle it has 43 count of knock and the guy that was gonna tune it siad he couldn't because it was too high, and it would not be tunable.

 

[JayRolla]

Yeap you have PK. It is a huge pain to tune around. I run dsmlink so my knock sensor doesnt kick in till full boost and or 60% throttle. It helps a lot. I run e85 so when I really am running the car I end up disabling the knock sensor since it loves to show false knock. Huge 6 bolt issue that sometimes seems impossible to fix.