Knock Sensor/Knock Gauge Problem

[RonAnders]

I just bought an 87 Grand National and have noticed my knock gauge lights are not coming on at all, only the green center light showing its on, car runs fine when cruising or slightly getting into it but once I step on it you can hear a loud knock or bang. Im guessing extreme detonation definetely timing issue. Is my knock sensor itself bad? It has an upgraded chip, performance cam and pistons from what ive been told, previous owner cant be reached, running 93 octane. Any help from my new brotherens would be appreciated

 

[TurboBuRick]

Howdy,

Does the gauge show anything when starting the car? You can tap on the knock sensor with something to see if it works. It's under the coil pack and module. You will need someone to watch the gauge when you tap on it.

Does the car nose over when you hear this bang?

 

[pacecarta]

what does the scanmaster show for KR when you step on it " ???
whats the boost when you "step on it" ???.. if you dont have a real boost gauge get one
whats the o2 reading when you"step on it "???? ... look at your scanmaster

 

[69RSCLONE]

Are you sure it's detonation? That will sound more like shaking a coffee can with marbles in it. Does the noise only bang once when you get on it, or continuous? A one time knock or bang sounds more like a torn motor mount.

 

[RonAnders]

Hey guys, thanks for the responses, the green center light comes on when i start it, i will try hitting it and have somebody watch the gauge. It doesnt really nose over and its a couple of bangs/pops before I let off. Just got the car Saturday, engine and trans were rebuilt 4k miles ago, havent got a scanmaster yet but it seems like everyone says its a must have. When I looked it over today i noticed the coolant resevoir was completely empty minus a brown liquid at the very bottom, after removing the radiator cap i noticed a little of the same at the top of the green 50/50 mix, should I flush it out or just fill up the resevoir tank? thought low coolant level might be causing the bang/pop problem. New to all this and have a lot to learn by the looks of reading posts everynight, Appreciate the help boys!!