Does to much fuel = Knock??

[b15turbo]

Ok i just got my car back and i have all the fuel in the world with fuel pump and 880ccs. Now I'm running 57 trim turbo 17psi only and tons of knock but on the safc we added like 15+ to 20+ on high rpms and still knock can that knock be because im running to rich ??? I would think with supra pump and 880cc injectors should be fine, what do you think?

 

[dnhieu]

yes running rich can cause knock. do you have anything to regulate that fuel pump??? anything to control the ruff idle of the 850cc injectors???

 

[andymoraitis]

He has an EPROM ECU for fuel control on the injectors.

Yes, too much fuel can cause rich knock. You actually need to set the AFC to zero to get to a 9.5:1 A/F and lean it out more from there to hit your target. As of know you're drowing the motor in fuel. At least zero that thing out and work from there.

 

[b15turbo]

the bad thing is that my logger doesnt work so i only have knock gague to go by but its just i add fuel and it still knocks..

 

[andymoraitis]

You're not getting this. You need to take fuel away NOT add it. Since the chip compensates for the injectors, you can set the AFC to zero all the way across and it will take the base air/fuel ratio to stock targets (9.5:1). Since that's better but nowhere near optimal, you can start subtracting fuel on the AFC to lean the motor out while watching for knock.

As I said before adding fuel will make you run richer and drown the motor. This is very like the cause of your knock if you're running +20 to +30. You want to lean the motor out in small increments after re-setting everything to zero (i.e. -5 to -10) and see how she reacts with respect to knock. While you're at it make sure that your base fuel pressure is 37 psi with the vacuum line off as higher fuel pressure will aggravate an already rich condition and make it worse.

Also, I'm not trying to be difficult but if you don't know how to tune the car, get it to a dyno facility that can or start searching for AFC adjustment threads that will get you in the ballpark.