Chasing On and off again spark knock.

[Ttype6]

I would assume not FP is new

You can't assume anything. If you have the original regulator,you should put it on and see how it acts. It costs nothing to do this.

 

[Ttype6]

Every time I've gone full WOT and had no knock my 02s were in the low 800 range.

You need to observe the O2 reading when it does spark knock,not when it doesn't. You've illustrated two examples of when you noted spark retard but didn't share any o2 reading. You've witnessed your changing fuel pressure and haven't bothered to observe it at full boost. You must do this to,at least,determine if you have a fuel delivery problem. The evidence you currently have leans heavily toward a fuel delivery problem. Look at WOT fuel pressure and o2 readings and turn the boost down.

 

[kking89]

You need to observe the O2 reading when it does spark knock,not when it doesn't. You've illustrated two examples of when you noted spark retard but didn't share any o2 reading. You've witnessed your changing fuel pressure and haven't bothered to observe it at full boost. You must do this to,at least,determine if you have a fuel delivery problem. The evidence you currently have leans heavily toward a fuel delivery problem. Look at WOT fuel pressure and o2 readings and turn the boost down.

You think I'd turn the boost down to say 15 psi and do 1-2 wot pulls it won't hurt anything? From what I heard 15 psi can take a pretty good amount of kr for sometime before blowing.

 

[SCOOBY DOO]

What you need to do is verify your fuel pressure is rising 1 for 1 with boost. Put Erics chip and Julios alky on default...and go out and lean into it...watching fuel pressure...and keeping an eye out for KR. PL would be handy.

 

[kking89]

What you need to do is verify your fuel pressure is rising 1 for 1 with boost. Put Erics chip and Julios alky on default...and go out and lean into it...watching fuel pressure...and keeping an eye out for KR. PL would be handy.

Yea I just don't want to blow the motor going wot like that, but I gotta get numbers somehow I guess right. That's the only way really. I talked to Eric a bit too he mentioned turning my boost down to 15 then turning the timing down 3 degrees then do a wot pull and see what numbers I get.

 

[SCOOBY DOO]

You can just slowly lean into it...and watch the fuel pressure gauge. If you have the knock gauge on the A-pillar it's in your line of sight...and if you see a hint of KR let out of it.

 

[dynoman]

We just had a similar problem on here with static fuel pressure changing after setting it with a new regulator & pump . Turned out to be the short hose , in-tank from pump to sender . You need FP readings while driving , if the pressure is dropping off it will show as soon as demand increases , as in 1 , 2 , 3 , 4 psi of boost . Remember 1 for 1 , boost & FP .
Where are you located , maybe someone near by could help . Sam

 

[kking89]

You can just slowly lean into it...and watch the fuel pressure gauge. If you have the knock gauge on the A-pillar it's in your line of sight...and if you see a hint of KR let out of it.

Yes I have a kirban knock gauge on the pillar. I also bought one of those FP gauge kits from autozone that comes with a hose. I know it's not super nice but should get the job done for this little test.

 

[kking89]

We just had a similar problem on here with static fuel pressure changing after setting it with a new regulator & pump . Turned out to be the short hose , in-tank from pump to sender . You need FP readings while driving , if the pressure is dropping off it will show as soon as demand increases , as in 1 , 2 , 3 , 4 psi of boost . Remember 1 for 1 , boost & FP .
Where are you located , maybe someone near by could help . Sam

I am located in st.louis county.