Hi - I have an 89 GTA 5.7 TPI. I installed vortec heads, sd vortec intake, edelbrock headers. ZZ4 cam. All smog stuff intact.

When I went to start tuning I couldn't stop getting knock retard. I am back to the stock prom (ajup). Base timing is 8 degrees. I kept adding to the base timing in the prom until I took out whole 14 degrees of advance - I still get knock. I started adding fuel and doing runs. I have a wideband and I am running close to 11:1 at WOT. Still knocking. I ran a dedicated wire from the knock sensor to the esc module and a dedicated ground to the module. Same results. Also replaced the knock sensor. No difference.

Here's a log if anyone can check it out and give me pointers:
http://members.bellatlantic.net/dantill/rewire.csv

thanks in advance for any tips - I've been at this a long time and I am very eager to figure this one out!

 

Maybe verify the timing with an advance timing light.

 

You can't log using the $32 DM if you have a 730 running $8D.
Try logging with the $8D version or otherwise change to a MAF memcal/bin.
AUJP is $8D (SD, not MAF)
I'm confused, what is your setup

 

I am running MAF - I will double check tonight but I am sure I'm running the right memcal - I just got the names mixed up in the message. I have the "165" type computer. I was running with arap before but I switched back to stock and dialed back when I was getting knock.

 

Other thoughts - I hear no pinging/knock, and the car runs great with arap other than the knock. With all the timing removed not very responsive (base timing in PROM at about 22 deg), so I know that's working. I did have the cam, heads and intake off, and I am an amateur, so maybe I did something to throw off where the timing mark is?

 

When you check the base timing, you are disconnecting the EST wire correct?

-jason

 

You're sure there's no mechanical issues? No loose rockers or worn bearings? I've even heard of worn valve guides causing a sound that the KS might pick up as knock.

 

I will consider that as a possiblity.

Engine has 55k original miles, L98. Heads are new Vortec. Burns no oil or anything. Knocking starts when I floor it.

I remember following a procedure in the manual for torquing the rockers, they seemed pretty tight.

 

I just read an EGR issue can cause knock.

Can I just diable EGR in the PROM to rule it out as a cause of knock? Also, I have no codes, either.

 

just looking at my old messages - dropping 1 heat range fixed it (R44 to R43 AC plugs)

 

if it runs well and only knocks when you floor it, try taking some timing out of the PE table...

 

If you pulled timing the knock was still there i would say its false. Disable the knock sensor or desensitize it a bit and be done with it.

 

How do you do that?