40 ounts of knock! [Archive] - DSM Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum: DSMtalk.com

: 40 ounts of knock!


1990TalonFast
12-06-2010, 08:53 PM
My logger has been reading tons of knock, at cruising speed its around 30-40 but at wot it drops to 20-28, at idle its at 6-9 :confused: why am I getting these crazy readings?

Fejery4491
12-06-2010, 09:22 PM
You might have something causing a vibration which your knock sensor is picking up as knock.

J_DiZ
12-06-2010, 09:49 PM
Do you have other than stock pistons?

1990TalonFast
12-06-2010, 10:04 PM
Do you have other than stock pistons?

No sir.

shott17
12-07-2010, 06:54 AM
Maybe it is because you installed a substandard fuel pump and its actually knocking because you are running too much boost for the fuel to keep up with. Because it was free, and you don't want to spend money. :rolleyes:

1990TalonFast
12-07-2010, 03:40 PM
Maybe it is because you installed a substandard fuel pump and its actually knocking because you are running too much boost for the fuel to keep up with. Because it was free, and you don't want to spend money. :rolleyes:

I have the factory pump installed and rewired with 10awg wire and running 16psi, pump is getting 9.3v before boost even hits, cruise and idle its 14-18v, I think mmcd is reading a faulty voltage.

1990TalonFast
12-07-2010, 03:43 PM
The fuel pump voltage literally stays stuck at 9.3v whe the boost hits and wont budge so that's why I suspect mmcd reading is bogus, I will back the boost to 8psi till I get a voltmeter reading that can confirm.

CoxAbele
12-07-2010, 07:48 PM
wait wait wait wait wait.... did the fuel pump re-wire to the battery and are only seeing 9.3 volts?

1990TalonFast
12-07-2010, 08:23 PM
wait wait wait wait wait.... did the fuel pump re-wire to the battery and are only seeing 9.3 volts?

Correct, I am going to try placing the ground somewhere else, I don't even know if mmcd is accurate with the fuel voltage.

CoxAbele
12-07-2010, 09:02 PM
Did you also add a bigger ground wire? If you didn't that could be a large part of your problem. Without a sufficient ground, the entire pump electrical system, including your new wiring, can't handle the resistance. Find a bare metal ground, or make one, then with a volt meter actually test the voltage at the pump wires. You should be seeing 13-14v with the car running and the 10g wire disconnected from the pump (you can check this at the relay pretty easy). If you have a sufficient ground and you see 13-14v while the power wire is disconnected from the pump, but only 9v when the pump is running, that pump is on it's dieing leg or your fuel pressure is through the roof.

1990TalonFast
12-07-2010, 09:11 PM
I sanded down some paint in the trunk and bolted the ground down there, IDK if that is a good spot or not. The ground wire is a 10awg wire.

CoxAbele
12-07-2010, 09:54 PM
For the sake of resting, run that ground wire all the way to the pump and let us know what happens with the voltage.