From stop-no knock, from roll-much knk

[Mike70gtx]

First of all I'm trying to tune with a turbo-link that jumps all over the place. So with the knock guage and fuel pressure, I'm trying my best. From a stand still, I can run it through 3 gears with no knock and a shot of alky at about 10 pounds of boost and going up to about 15 to 17 pounds. If I step on it from a roll (10 to 50mph) it will show knock on the guage (caspers) from moderate to severe. and you can hear it. I have a red armstrong chip that I think is pretty aggressive. I turned back the timing on my trans plus about 4 degrees.
Any help?

 

[turbo6x2]

You are going to want to check make sure nothing is hitting, this will give you knock. Check motor mounts make sure they are good, check exhaust make sure it's not hitting under neath. Just wiggle things to see if anything is loose. We just worked on a 85 that had a broken motor mount, now he's not getting as much knock (whole motor was rolling)but he still has to secure his radiator and k&N filter that is loose. Let us know what you find. Take care.

 

[Mike70gtx]

thanks, I'll check it out.
Any other ideas, anyone?

 

[JayLashua]

turbolink jumps all over? the data, or the laptop ?? ;p

record the run and see how the O2 mv look, basically when you floor it from a stand still, it runs differently from how you would during a cruise, and stab-in.. since you dont get knock from astandstill, see what the o2 mv look like when you punch from a roll, stay in until you get into red.. stop, playback the recording...

 

[Mike70gtx]

My data jumps. Sometimes it stops flowing. Sometimes every other frame or so jumps. It might actually read the right mph and the next frame it will peg out. Blm's are usually low, 100 to 110. O2s seem low too. I've turned the fuel pressure up and down and results on turbo-link don't seem much different. If I get below 40#s fuel pressure it doesn't run as well.
Could 02 sensor be bad even if it doesn't throw a code? I might try another ecm.

 

[JayLashua]

Well if you have another ecm to try give it a shot, otherwise, make sure theres no problems with the turbo link cable itself.

An O2 will start going bad gradually, the cross-counts will become slower and it will be less accurate, but it's not until the thing is either DEAD or quite close to not working at all that it throws a code.

 

[Mike70gtx]

Already sent cable in and it's good. I've got a heated 02 sensor on the way and we will see what happens.
thanks