you want to call it. After a rebuild the car pings, had the pcm (multiple ones) changed by Bryan at pcmforless.com with no success. Checked fuel pressure it is good, -12cc pistons were used so its not compression too high, the timing has been moved multiple times by Bryan at pcmforless, it gets 1 degree of KR at idle when in drive? after shifting into 2nd with a load it shows 5-6-7-9 degrees of knock retard. Pulled timing cover and gears are not off (chain has some slack) but that wont cause what I am having, I think. You named it I have tried it, adjusted valves while it was running. ANYONE?????? this is a 383 by the way, has the hotcam. has accel injectors 30 pounders and adj fuel regulator too.

 

Dont have your answer...but I sure hope this doesnt happen to me. Im rebuilding my engine(new shortblock, ported heads, hotcam kit) because of detonation/ping that wont go away. Its been a problem for me for over 1.5yrs. Got really bad once i started spraying nitrous into in all the time. I have tried everything from all new sensors(you name it, its new on my car), fuel pump, injectors, tuning with LT1 edit, leaky egr, pcv, exhaust gasket, intake leak, seafoam, opti, plugs(many sets), plug wires, bad wireing, coolent problems, etc.....lieterally, I have done it all. Still have/had audiable ping. So i am rebuilding the POS in hopes of curing my PING. If it doesnt go away after this...im selling my car. At least it will be all new and with lots of performance...someone will buy it. Keep us updated if you find the cure.

 

tried a different coil too. Eliminated the egr, cat and air pump and it was programmed without all this.

 

02's in the 900's I just cant figure it out.

 

do you still have egr on the motor? maybe the valve is stuck open.. I can't relaly think of anything else.

 

how did it look when you pulled it apart, pistons OK or broken rings?

 

Mine did that & I just Zeroed out the KR table, its all fake, I have the LT4 KM aswell, no difference. But resently I put the KR back on & there was no KR anymore ??? weird went away, using water istead of coolant can cause KR aswell, header leak will definetly cause KR. stuff like that, also if your KR wire is close to your spark plug wires it'll cause KR aswell.


Or do you acctually hear/feel it?

 

block off plates on intake and exhaust manifolds

 

I think what you might be hearing is an exhaust leak which is setting off your KR.

 

like marbles in a tin can and once it starts you keep going with the pedal and it gets louder and nastier.

 

I know a exhaust leak and knock, this is a nasty sound.

 

You may have done this...try a different brand of gas,and some octane booster.

 

No booster or tolulene yet, should not need that with -12cc pistons, should be well below 11:1

 

plugs, has new wires, injectors are new, cam is new, has 100 pound springs, new fuel filter, new air filter, you name it, I have tried it.

 

how much piston to deck clearance at TDC?