high knock

[aaparker]

have a 97 gst. when i start my car my knock is fine, reads o and fluctuates a little when at idle. 0 at throttle. but overtime as i am driving the knock increases slowly. idle or acceleration doesn't matter it starts to climb and will not drop. after about an hour of driving or so the knock count is at or above 30.
i had my afc dyno tuned about a year and a half ago only mods since have been a 1g throttle swap which to my understanding shouldn't have changed my a/f because the mass flow would compensate for the extra air, and a boost controller. I am boosting at 13-14 lbs. which should be acceptable on a stock 2g system. ? any help would be appreciated.

 

[greddyturbo19]

do you use Premium gas? just a thought.

 

[aaparker]

yep, we only have 91 in the area but yes definitely.

 

[greddyturbo19]

i doubt that might have something to do with it but here in florida we have 93 octane which i think is the recommended rating for the turbo well we also have 100 octane too but damn thats too expensive.

 

[anteversion]

this is not that bad. some little knock like that is not the real knock that can destroy your engine. Real one is like 15-17-20- maybe 30 counts in one pull with full throttle applied. you are talking here about knock sum this is not the same thing. it is normal for an engine to '' pink '' a little

 

[aaparker]

thats at idle

 

[dsmmatt28]

Bad knock sensor

 

[aaparker]

I would agree about the bad knock sensor but I am getting a sputter out of it every so often that sometimes kills the car. The car won't start for a while, then it will run again like it never happened. I was also getting a misfire code but it went away after I regapped my plugs. So I think there is a problem regarding my air to fuel. I know I could remedy it with the afc but I want to find the source, not cover it up.

 

[Gstclipse69]

Have you done a boost leak test?

 

[aaparker]

yep all good there. any other thoughts?

 

[jking29]

I would agree about the bad knock sensor but I am getting a sputter out of it every so often that sometimes kills the car. The car won't start for a while, then it will run again like it never happened. I was also getting a misfire code but it went away after I regapped my plugs. So I think there is a problem regarding my air to fuel. I know I could remedy it with the afc but I want to find the source, not cover it up.

Have you checked fuel pressure? A fuel pump going bad can cause these symptoms too.