A question about my fuel pump and knock

[cyclonekid77]

Ok, currently my car is running stock boost on my big 16g. It starts knocking around 5-6k rpm. I have a wally 255 and I havent rewired it yet. Could that be the cause of my knock? Im thinking the pump drops off at the higher rpm and the car leans out and knocks? I plan to rewire it tomorrow but I got to thinking about what is causing my knock and this was one of my ideas. The stock sidemount probably doesnt help either... Any information/suggestions would be great. Thanks

 

[marq95gst]

What are you running for boost (psi)? Have you messed with the timing? At stock boost (9-11psi) your sidemount is not going to be the problem.

 

[cyclonekid77]

Yea 9-10psi. The timing is set at 2 deg rite now.(base timing)

 

[cyclonekid77]

So could my fuel pump be causing my knock?

 

[ericmetcalf11]

Base timing is 5* (Base Timing Adjustment)

Could be a lot of things and rewiring doesn't hurt and eliminates one potential issue. Easier to track down the issue if you could use a logger or wideband.

 

[cyclonekid77]

I have my timing at 2* because it REALLY knocked at 5*. I did the rewire today and it didnt help the knock at all either.

 

[dylnwit]

Your running 93 or better gas right? Are your plugs good and gapped correctly? Is your knock sensor in good shape? Just throwing a few simple things out there that may help the issue. Knock could come from a lack of fuel (the ecu uses some extra to cool the combustion chamber) but with a 255, your more likely to have too much fuel unless you have an afpr. Start with the simple things and go from there. Is it audible knock, or are you using a logger? Check the sensor first, it's been known to go bad from the heat over time and send random knock counts.

 

[cyclonekid77]

My car never sees anything less than 93 octane. The knock sensor is a fairly new oem one. Its not an audible knock, I have a stage 3 keydiver chip from jeff with the stock boost gauge converted to knocksum. Its starts showing knock around 5k rpms. Im just kind of running out of ideas other than a meth kit or a frontmount.

 

[red_devil]

The 255 is more than enough for your mods. You may be running too rich if you dont have a fpr. Also check the knock sensor connection, when mine was not connected correctly my knock gauge would spike on and off.

 

[Calan]

Get something...anything...to log with before even considering a meth kit or a frontmount. Figure out what's going on with your car, instead of shotguning the problem.

With that mod list, you really should have a wideband and a good logging/tuning package by now.

 

[5150DSM]

There's a good chance the pump is overunning your stock regulator. Get an adjustable FPR to stabilize fuel flow, you can tune from there. A steady baseline fuel pressure is critical to tuning at any boost level.