S-Mode Quirks

juld0zer · 10-07-2013, 08:22 PM

mine has been a bit sloppy since i picked it up (second hand).
Now it's really jerky, going from 3rd to 4th feels like a first time stick driver (jolt).

i adjusted the clutch pedal sensor (the one that detects when the clutch pedal is fully depressed) but that didnt improve much.

next suspect is the input speed sensor and its loom. really disappointed as it ruins the experience of the car and makes me hate driving it :|

SouthArk370Z · 10-07-2013, 09:03 PM

Just a wild guess but have you checked the "stick position sensor"? It may be out of alignment.

juld0zer · 10-07-2013, 09:24 PM

it's a possibility i pondered but it's also the least accessible of the 3 sensors (well, four if you count the axle ones as two).

i dont want to drop the box and have to replace the CSC etc as a result :|

The gear display on the gauge cluster displays the gears correctly though.
Is there a simpler test?

Another reason i suspect the input speed sensor is because the revs never seem as accurately matched as all the reviewers claim. ie. not 'perfect precision'. To the point where i think i could do a better job!
And downshifting to decelerate is always a clunking affair.

The same type of sensor is also the one responsible for jerky rough shifts in automatic boxes on other cars.

I hope i dont have to inspect the gear position sensor

juld0zer · 10-08-2013, 11:04 AM

It's early days for me but i think i fixed mine. My sloppy SRM action (not enough blip resulting in rough unpredictable shifting) was due to fine metal particles stuck to the tip of the input speed sensor. The sensor is on the left side of the gearbox almost perpendicular to the rear cat flange. I found no visible damage to the loom due to heat or physical damage.
Think of the crap that gets stuck to a magetic engine oil sump plug. That's the amount and fine-ness of this silvery coloured substance i found on the tip.
From my experience with these type of sensors, any metal on the tip can interfere with signal production.
The same type of sensor is responsible for sloppy shifts in automatic transmissions of orher cars.
There seriously wasnt much of this material on the sensor but cleaning it was enough to restore smooth up and down shifting at various rpm. No more holding breath as i re engage clutch!
I will report back in 1000km to see if it holds up. but i will look into fitting a magnetic gearbox drain plug to keep those metal particles at bay.

10-07-2013, 09:03 PM	#17 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324198	Just a wild guess but have you checked the "stick position sensor"? It may be out of alignment. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

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10-07-2013, 08:22 PM	#16 (permalink)
juld0zer Enthusiast Member Join Date: Nov 2012 Location: Sydney Posts: 428 Drives: 11 Nissan 370Z MB M6 Rep Power: 139	mine has been a bit sloppy since i picked it up (second hand). Now it's really jerky, going from 3rd to 4th feels like a first time stick driver (jolt). i adjusted the clutch pedal sensor (the one that detects when the clutch pedal is fully depressed) but that didnt improve much. next suspect is the input speed sensor and its loom. really disappointed as it ruins the experience of the car and makes me hate driving it :\|

10-07-2013, 09:24 PM	#18 (permalink)
juld0zer Enthusiast Member Join Date: Nov 2012 Location: Sydney Posts: 428 Drives: 11 Nissan 370Z MB M6 Rep Power: 139	it's a possibility i pondered but it's also the least accessible of the 3 sensors (well, four if you count the axle ones as two). i dont want to drop the box and have to replace the CSC etc as a result :\| The gear display on the gauge cluster displays the gears correctly though. Is there a simpler test? Another reason i suspect the input speed sensor is because the revs never seem as accurately matched as all the reviewers claim. ie. not 'perfect precision'. To the point where i think i could do a better job! And downshifting to decelerate is always a clunking affair. The same type of sensor is also the one responsible for jerky rough shifts in automatic boxes on other cars. I hope i dont have to inspect the gear position sensor

10-08-2013, 11:04 AM	#19 (permalink)
juld0zer Enthusiast Member Join Date: Nov 2012 Location: Sydney Posts: 428 Drives: 11 Nissan 370Z MB M6 Rep Power: 139	It's early days for me but i think i fixed mine. My sloppy SRM action (not enough blip resulting in rough unpredictable shifting) was due to fine metal particles stuck to the tip of the input speed sensor. The sensor is on the left side of the gearbox almost perpendicular to the rear cat flange. I found no visible damage to the loom due to heat or physical damage. Think of the crap that gets stuck to a magetic engine oil sump plug. That's the amount and fine-ness of this silvery coloured substance i found on the tip. From my experience with these type of sensors, any metal on the tip can interfere with signal production. The same type of sensor is responsible for sloppy shifts in automatic transmissions of orher cars. There seriously wasnt much of this material on the sensor but cleaning it was enough to restore smooth up and down shifting at various rpm. No more holding breath as i re engage clutch! I will report back in 1000km to see if it holds up. but i will look into fitting a magnetic gearbox drain plug to keep those metal particles at bay.