New det sensor and new sub harness but still code 34

Agree. I'm just thinking that if the sensor resistance is way wrong in the first place then detonation may push it into the range where the ECU raises a code 34. I can't think of any other way to explain why the bypass works (suggesting no wiring fault), yet he gets a code 34 and detonation with no bypass. It would be interesting to know the resistance of the sensor.

 

That is it exactly. The resistance of the replacement sensor is not the same as the original OEM. Hence voltage out of range and code 34. It seems to suggest that not all knock sensors are the same.

MichaelZ.

 

Just be aware that if you have an aftermarket pressure regulator and the pressure is accidently set wrong - it can continually trip code 34 even though the sensor and cable is perfectly fine.

It happened to me and after I ended up with new sensor/ cable, I still had the same problem, then I checked the fuel pressure and reset it correct to specs - it fixed the problem immediately and have had no code 34 since so I decided to continue running the original sensor and harness as well.

Also - read a tech statement somewhere that said that the detonation sensor has to be tightened to the correct pressure and cannot be too tight or loose as apparently this can affect the operation of the pickup - just something worth remembering when installing them

 

There may be more to it.

Found this article. It seems that the tightening torque affects the sensor. The manual does not state the torque. the article does but it is not official from Nissan.

MichaelZ

 

Had some fun this weekend. Installed a different CAS and adjusted to 15 degrees BTDC, idle to 700 RPM and TPS to .42v.

Ran 95 on Saturday which was a hot day as 98 wasn't available. Pinged around ~2000-2300rpm compared to old CAS which did from ~1700-2300rpm on 98 octane.

Went to a servo with 98 octane, filled up and added a bottle of octane booster which claims to add 7 ron to 60l and I had zero detonation in hot weather which is great.

The parts car I took the ECU off had a sticker on it for stock settings and recommended 100 RON. I am guessing Australia's equivalent is 98 pump fuel?

 

Nope, 98 pump fuel is 98 octane or less. The only pump fuel I'm aware of that's 100 octane or higher is United's Premium 100, or E85.

 

Let's keep in mind that the ECU does nothing with the det sensor over 3000ish rpm.

 

The ECU may not listen for detonation above a certain RPM, but once you are into knock maps, then you are stuck there until you restart the engine (assuming you are not immediately back into a code 34)
Knock maps certainly do have adjusted timing and fuel across the entire RPM range and engine load conditions.