knock.;

[syclone#2659]

im having problems with knock, i have the truck running great right now, but still getting 1-5.2 knock at wot, stock boost. i have the fp set at 44 base, and i have a walboro. temps are good. the only thing i can think of is my exhaust. i have the muffler cut off and havent put a pipe in between yet. i still have the cat. but the sound from the exhaust is exiting underneath the truck not out the back. would the vibrations, cause it? i have the datamaster run file if somone wants to host it 4 me.

 

[syclone#2659]

Re: knock.;

after looking at my file . i see that at wot.@3300rpm's and 14.3 lbs of boost. spark advance 8.1, Ia temps @96 degrees i have 4.4 spark retard. my o2mv are at 888, and injector DC 84.4! that is alot on the injectors should i turn down the fp to 42lbs? i noticed the knock come around when the injector DC got around 70. im getting frustrated

 

[leroy]

Re: knock.;

Don't use injector duty cycle to tune. Use it to decide when to get bigger injectors. Fuel pressure at wot will have no impact on injector duty cycle.

I would try raising the fuel pressure. Of course, you may have other problems causing the knock.

HTH,
Jim

 

[NecroWolf]

Re: knock.;

isn't fairly rich on the 02 sensor?

 

[leroy]

Re: knock.;

isn't fairly rich on the 02 sensor?

888 mvolts is richer than stoich (14.7:1). At WOT, 12:1 or richer is what you want. There's no way of knowing what a/f ratio 888 mvolts is (unless you have a wideband) . Even with wideband, a narrowband sensor's readings may vary based on age, use, and temperature.

Jim