Oh no! Knock! Help

[darb]

A little about my car first. 87 GN with 37k miles on it. Mods- Walbro 340 with hotwire, afpr, k & n cone, 30/30 boost gauge, Caspers knock gauge, scanmaster 2.1, ATR 2.5 SS exhaust, gutted cat, Poston 3" DP, Postons driver side header, Hi-Effieciency radiator, 160 stat, fuel pressure gauge, completed all Spring cleaning procedure within last 600 miles. Here is my problem. Took the car out today and was crusing about 30-35 mph, nailed the gas, and my knock gauge lit up to the 2nd amber light and the scanmaster showed a max 6.3 kr. When I get on the gas gradual, I get no knock, but wot from a stand still or from a roll, it's starting to knock. This hasn't been the case in the past. Running 16-17 psi, 42 off-line fuel pressure, and had been getting no knock. I took the car to have the rear main replaced and had regular oil put back in besides synthetic. I was running synthetic before, but this shouldn't give me knock should it? Also, I was told that my crossover pipe is not sealing up like it should. So, I'm leaking exhaust from the crossover because I have not installed the passenger side header yet, its still stock. Will this cause knock? These are the only things I can think of that could be casuing this. Let me get some input from you guys. Have to get this knock outta here. Sorry for the long post, didn't want to leave anything out, or at least tried no too. Thanks.

Brad

 

[blackbuick87]

It is probably something simple. I dont see what chip you are running but if you didnt change it that is probably not the problem. May just be bad gas. Mix in some xylene or race gas (if you dont have a cat) and see if it goes away. Or maybe a motor mount is going bad allowing the motor to twist a little. Check the fuel filter too

 

[darb]

Forgot the chip, knew I forgot something. I have a Gary Mitchell 93 chip. Car has run fantastic with it so far. I have a brand new fuel filter and the car should be good, no reason it shouldn't be. Any other suggestions what could be wrong? Thanks

Brad

 

[darb]

Anyone got any other ideas what I can be doing wrong?
Please hekp me get rid of this knock. Thanks

Brad

 

[V6POWER]

Brad...What fuel pressure regulator do you have? I had knock for years that I could not find the cause of. It turned out to be caused by my Bowling Green Custom afpr. It would show that it was flowing pressure, but it was not flowing volume.

 

[darb]

I think it's a Kirbans billet afpr. It was given to me by the previous owner and I installed it. It has been working up till now so I dont know why it just stopped. That could be it though I guess if it's a bad regulator. Which would be a good way to check this and find out? Any ideas?

Brad

 

[darb]

Anyone know how to check the regulator to see if that's my problem? If that is not it, what else could it be? I think my O2's were 856 at the max of 6.3 kr. What do you think? Any more ideas? I'm lost on what to do next.

Brad

 

[gnturbo]

with a 856 it is runng a litle rich,what are your "bl" readings?maybe it is a "rich"knock like some one in another post implied about my problem.I have never heard of "rich" knock until today.Any body,anybody?also anybody know what the increments of knock that are represented by the green amber and red lights on the casper knock gauge?