Strange kr issue

[SyTyAddict]

Is there any significance with the exact number 12.66* kr? I know that if the knock sensor is bad or unplugged it defaults to 4.04* The first time I launched the Sy it maxed at 12.66*, but strangely this was at about 20% throttle and still under vacuum, after it went into boost and throughout the run it leveled out to about 8-10*. Any time it goes to a high kr # it also maxes exactly 12.66* and will do it every time I log it, but it has never surpassed 12.66*. I was having issues with kr at idle (up to about 5*), but I have eliminated that issue be reseating the ribbon cable from the prompaq, it was slightly loose. I have occasionally seen it hit .5* at idle, but that rarely happens.

I know that that is a lot of knock and I've only gone WOT about 3 times, I am not getting into boost anymore until I get this figured out. The way it acts, it ,makes me wonder if its not an issue with the ecm or the chip. I plan to go code59 soon, but would like to try to figure this issue out before I do that.

Thanks,
Clay

 

[SyTyAddict]

Re: Strange kr issue

I just thougt to search that #, apparently 12.66 is the max timing retard on a stock style chip. Does it seem odd that it has so much kr under light throttle? I'm thinking some race gas is in my future to see if it seems to be real knock.

Sorry if it seems like I'm answering my own questions. If anyone has any suggestions, they will be appreciated.

 

[WyoSyclone]

Re: Strange kr issue

Sounds like false knock if you're seeing it at idle and very light loads. Check the downpipe, fuel lines, motor mounts, etc. to see if anything rubbing, moving, vibrating.

 

[bezerk]

Re: Strange kr issue

that sucks, you got false knock prolly. maybe try to move the Knocksensor

 

[SyTyAddict]

Re: Strange kr issue

The knock at idle is pretty much gone, but it has a lot of knock sometime to not even be in boost. I can tell the exhaust touches the torsion bar crossmember, surely it would not show that much knock being that far from the engine. It still has rubber motor mounts so it probably moves a good bit when being brake torqued. The dp has about a 1/4" of clearance from the frame in one spot and has touched at some point in its life, but it doesn't touch when being free revved in park, but under load it might.

It has a built motor and roller rockers, but I would think it would be picking that up all the time and not just when being launched. I hope it is false knock, if it is real, then thats alot of abuse on the bottom end.

 

[BMFB]

Re: Strange kr issue

if it was real knock and it was that bad, you'd prolly hear it. its most likly false, check the downpipe where it bolts to the trans, flexplate, stuff like that. But fromw hat you say, Id get soemthing like a high temp glove or soemthing, and jam it between the crossmember and the pipe, and do a quick run, before it bursts into flames. before that though, i'd look into your ruber mounts, they may be going out and letting the motor rotate in the bay more than it did before, brake torque it, and check it out with the hood up.

 

[SyTyAddict]

Re: Strange kr issue

I'm planning on doing a engine tied down soon, eventually I'll probably go poly or solid mounts. The glove idea you mentioned is a good idea, I'll give it a try tomorrow. This might seem overkill, but I might unhook the wastegate rod before I run it so the puck stays open, so it won't hurt anything incase it is real knock. I figure that if it the knock looks the same with the wastegate fully open, then it must be false. I've been driving it with the wastegate selenoid unplugged to try to keep the boost down incase I do have to get on it, the base boost is pretty high (11 psi).

 

[sy#2716]

Re: Strange kr issue

First thing I would do is fill the tank with c16 and make sure it is not real knock. Then if it is false knock you can start to narrow it down.

 

[Aeroking]

Re: Strange kr issue

the ECM has a ESC Max Allowable Retard. which is the maximum timing that the ECM will pull. That 12.66 might be that magic number, so the ECM wants to pull more timing, but its preset for a max of 12.66. :2cents:

 

[SyTyAddict]

Re: Strange kr issue

Tonight I disconnected the wastegate rod and fixed the flapper in the open position in the event the knock is real, I wouldn't be in boost. I have come to the conclusion that the knock is false, considering it will hit 9* at 6% throttle and 11* at 9%. I watched my mechanical boost gauge and never let it get any boost whatsoever. I'm now going to start tracking down the source of the false knock, which I'm nearly certain is the dp and exhaust.

 

[Daryl H]

Re: Strange kr issue

Checking the timing and see if the base is set to zero degrees.