knock sensor help - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

fullmetalx · 08-23-2007, 02:16 AM

Problem: code 34(knock sensor and/or circuit) keeps on reappearing. Clear the codes and after a test drive. shut off engine recheck codes and code 34 pops up again.

Vehicle: 1991 240sx se, no mods, ecu# 26, 89 octane gas

Procedures already performed: replaced old knock sensor with a new one because old one has it's housing was melted (old one still good though, reads ~520 ohms), checked for continuity on the harness between plug on knock sensor and at the ecu and it is good. checked continuity of knock sensor to ground and it is good. idle is stable ~750 rpms, timing is at 20`BTDC. Car runs fine but not the best. Been this way since i bought it. Puff of bluish white smoke coming from the exhaust once in a while usually from a first time revving or start to accelerate in 1st gear.

I'm stumped as to why the code keeps on reappearing. could there be another reason or another part that could trip off this code. Would my lower octane gas (89) do it. Highest here in san diego is 91 octane. should i try that? I've searched thru Zilvia and the FSM. I've ran out of ideas. Any help would be greatly appreciated. Thanks.

08-23-2007, 02:16 AM	#1
fullmetalx Zilvia Member Join Date: Sep 2005 Location: san diego Posts: 189 Trader Rating: (5) Feedback Score: 5 reviews	knock sensor help Problem: code 34(knock sensor and/or circuit) keeps on reappearing. Clear the codes and after a test drive. shut off engine recheck codes and code 34 pops up again. Vehicle: 1991 240sx se, no mods, ecu# 26, 89 octane gas Procedures already performed: replaced old knock sensor with a new one because old one has it's housing was melted (old one still good though, reads ~520 ohms), checked for continuity on the harness between plug on knock sensor and at the ecu and it is good. checked continuity of knock sensor to ground and it is good. idle is stable ~750 rpms, timing is at 20`BTDC. Car runs fine but not the best. Been this way since i bought it. Puff of bluish white smoke coming from the exhaust once in a while usually from a first time revving or start to accelerate in 1st gear. I'm stumped as to why the code keeps on reappearing. could there be another reason or another part that could trip off this code. Would my lower octane gas (89) do it. Highest here in san diego is 91 octane. should i try that? I've searched thru Zilvia and the FSM. I've ran out of ideas. Any help would be greatly appreciated. Thanks.