I have been battling a nasty knock problem since I got the car months ago. I would max out the knock count with even stock boost settings and I was adding uber fuel via my 5 knooby AFC. Today I finally got around to investigate possible causes. The very first thing I checked turned out to be the cause. For some completely unknown to me reason, I was 17 degrees base timing. How it got that way, I have no idea. But after resetting it to 5 degrees(oddly enough I was still getting 10-15 degrees without the pin grounded?) I had to change my idle, which got rid of my idle surge(yay!). I then proceeded to change the plugs to BPR7ES's, I had hoped these would help against knock(without trying the timing first). While I was there I did a compression test, which mildly depressed me. 145-160-145-125(125 being closest to the T-Belt). Hopefully it is just valve seals as all the old plugs came out looking fine.
I cleaned up, fired her up and went for a test drive. I zero'd out the AFC and made some 2nd and 3rd gear pulls up to 7k with nearly no knock until the top(where it was only at worst 7 counts, nothing some time with the AFC can't fix).
All in all I am much happier with the car now, although I have to worry about that one cylinder, plus a new coolant leak I found coming from the front case(hopefully just a water pump so I can't my ass around to changing the T-Belt too). But I have a new found love for my GVR-4 which I haven't had in awhile. Who knew stock boost could feel so good.
Thanks for letting me share, and if anyone has any comments, feel free to share.
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