SR20det Red/Blacktop Knock Sensor Question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

***dorkidori_s13*** · 12-21-2013, 07:25 PM

My SR has been getting worse and worse lately as far as this little gremlin Ive had running around causing problems. Its narrowed down to either 1 of two things that I can think of...

1) BAD KNOCK SENSOR

2) BAD MAFS

The bad knock sensor is a definite as I hooked up the car up to Nistune when I put a new TPS in last week so I could properly set the IACV, TPS and Throttle Set Screw (to enable closed throttle flag). When Nistune checked my ECU, it found code 34 which is Knock Sensor Fail. I have a new knock sensor on the way and it will be here Monday.

In the mean time, I believe Code 34 can also relate to MAFS issues as well (my MAFS has never given me issues, its cleaned every month and I run a K&N Air Filter). The symptoms of the motor right now are CRAP gas millage and REALLY bad hesitation in accelerating at mid to full throttle between 1500-3400 RPMs (car pulls fine when in boost). There are no boost leaks, everything works fine in the engine.

So can anyone confirm to me what I already think I know. The car is in limp mode at the moment due to a faulty knock sensor (which Ive read causes all the symptoms I currently have). Has anyone ever had their knock sensor go out on them and pull code 34 from the ECU?

***dorkidori_s13*** · 12-21-2013, 08:37 PM

Ive done tons of searching in the subject over the last few weeks. I thought it would just be nice to engage others in conversation about the problem.

ultimateirving · 12-21-2013, 09:14 PM

Can't you turn off the knock sensor with nistune? I just did the resistor bypass and haven't had a problem since. But I plan to turn it off once I get some proper software

***dorkidori_s13*** · 12-22-2013, 12:10 AM

Quote:

Originally Posted by ultimateirving

Can't you turn off the knock sensor with nistune? I just did the resistor bypass and haven't had a problem since. But I plan to turn it off once I get some proper software

turning off the knock sensor on the factory ECU is a bad idea (even on a full tune its not a great idea to do). the knock sensor actually does retard or advance timing to help with fuel consumption or starvation. if you run a PowerFC, it helps you keep track of whats going on with your motor under harsher driving conditions.

OnTheChip · 12-22-2013, 06:53 AM

Code 34 is strictly for the knock sensor and has no relationship to the MAF. If you have code 34, the ECU will pull a constant 5º below 5000rpm.

Sounds like the MAF may be dirty.

12-21-2013, 07:25 PM	#1
*dorkidori_s13* ITS LISA'S FAULT!!! Join Date: Jun 2003 Location: Las Vegas Age: 43 Posts: 7,496 Trader Rating: (41) Feedback Score: 41 reviews	SR20det Red/Blacktop Knock Sensor Question My SR has been getting worse and worse lately as far as this little gremlin Ive had running around causing problems. Its narrowed down to either 1 of two things that I can think of... 1) BAD KNOCK SENSOR 2) BAD MAFS The bad knock sensor is a definite as I hooked up the car up to Nistune when I put a new TPS in last week so I could properly set the IACV, TPS and Throttle Set Screw (to enable closed throttle flag). When Nistune checked my ECU, it found code 34 which is Knock Sensor Fail. I have a new knock sensor on the way and it will be here Monday. In the mean time, I believe Code 34 can also relate to MAFS issues as well (my MAFS has never given me issues, its cleaned every month and I run a K&N Air Filter). The symptoms of the motor right now are CRAP gas millage and REALLY bad hesitation in accelerating at mid to full throttle between 1500-3400 RPMs (car pulls fine when in boost). There are no boost leaks, everything works fine in the engine. So can anyone confirm to me what I already think I know. The car is in limp mode at the moment due to a faulty knock sensor (which Ive read causes all the symptoms I currently have). Has anyone ever had their knock sensor go out on them and pull code 34 from the ECU? __________________ Check out my IG for what I'm up to! DORKIDORI INSTAGRAM!!!

12-21-2013, 08:37 PM	#2
*dorkidori_s13* ITS LISA'S FAULT!!! Join Date: Jun 2003 Location: Las Vegas Age: 43 Posts: 7,496 Trader Rating: (41) Feedback Score: 41 reviews	Ive done tons of searching in the subject over the last few weeks. I thought it would just be nice to engage others in conversation about the problem. __________________ Check out my IG for what I'm up to! DORKIDORI INSTAGRAM!!!

12-21-2013, 09:14 PM	#3
ultimateirving Zilvia FREAK! Join Date: Nov 2010 Location: arizona Age: 37 Posts: 1,521 Trader Rating: (1) Feedback Score: 1 reviews	Can't you turn off the knock sensor with nistune? I just did the resistor bypass and haven't had a problem since. But I plan to turn it off once I get some proper software __________________ Z32 with lq4 swap Desert Street Scene \|\| Dssevents.com

12-22-2013, 06:53 AM	#5
OnTheChip Zilvia Junkie Join Date: May 2013 Location: Burgaw, NC Posts: 318 Trader Rating: (0) Feedback Score: 0 reviews	Code 34 is strictly for the knock sensor and has no relationship to the MAF. If you have code 34, the ECU will pull a constant 5º below 5000rpm. Sounds like the MAF may be dirty. __________________ NismotronicSA - Speed-Density Tuning for Nissans