Knock Knock
 

Hey guys, I wonder if you can help me with another problem with my 87 GN. I received my heavy duty actuator last week from you and installed it. (fit perfect) I was able to increase my boost to the targeted 23 psi with my Alky control system. However I am still getting some knock (2-4 degrees) in 3rd at the top of the gear. I have the alky set about 6 on the blue knob and have moved it up to the max setting and it seams to get worst. I changed the plugs and noticed they look rich. My fuel pressure is set at 43 lbs with vacuum plugged. One other thing when I turned the alky back to 2 or 3 it seam to get better. My air/fuel seams to be in the area of 815 @ WOT 3 gear. Jose at alky control seams to think I should continue to increase the boost until it leans out. I am a little worried that I could loose a head gasket if I go much over 23 psi. As always Thanks for your help.

Your fuel pressure should probably be 43psi with the vacuum line off.

I removed the vacuum line and plugged it. Should I have left it unplugged and set the pressure?

No, that's fine, as long as you put it back on. :) When you got the knock, was it sustained or was it a blip then gone? Also what gap for the plugs. I'm not too worried about raising the boost, as long as your tune up is good. It's not boost that will take out your head gaskets, it's being too lean or detonation that takes them out.

Guys it is like this, I set the fuel pressure back to 43psi and the plugs are AC r43ts set at .032. I set the alky back to 6 on the knob and eased into it at 55mph. It started out ok for a second or two then I saw 4 to 5 degrees of knock and the 02 was reading around 870. I lifted and eased it back to the house. I then changed the program on the BLM from 128 to 124 (removed 3% for fuel at WOT) I took it out again and had .07 knock then it went away. It seemed like my 02 was still way off my target of 770 to 800. I was planning on taking the BLM down to 123 or 122 and trying that. It looks like to me that it is getting way too much fuel. Oh, the boost is set at 23psi in third gear.