SRM unique issue !

Smokey Nagata

2014 370Z and my Synchro Rev match feature is acting wonky with no warning or trouble light present. When downshifting to lower gears the Synchro Rev match will break up the car and bounce and buck about the rpms for about 1-2 seconds resulting in what almost feels like a mild misfire (while it decides on what it wants to do). I noticed it will also do this if I rev out 2/3rd gear without upshifting. The car will rev out fine until I let off the gas at high rpm and then the car will break up, and the rpms will take 1-2 sec to settle correctly ! If I turn the srm feature off the car has no issue and can row through the gears upshifting/downshifting without problem. I have attempted to reset the ecu multiple times and have checked the switches along the clutch pedal with no luck, the problem is almost intermediate as it first showed up for a short time 1 year ago and had disappeared until earlier this year when I turned the feature off for the first time in a long time. I daily drive the car and almost always have it on to make commuting easier.(My gear indicator also functions correctly). The problem almost feels like a nasty burble tune but its almost violent and unsettling for the car. I drained and refilled the trans with Motul Gear300 75w-90 grade about 20 months ago from today*

Has anyone ever seen this before on their car or have any idea what the culprit might be, I have researched on the forums and it doesn't seem to be a common issue at all as most people with SRM issues have the light illuminated and the feature does not function at all.

ZStalker505

sounds like when a newby drives a car with it activated and wiggles the shifter after taking it out of gear in neutral and it will blip the auto revs violently. Maybe something related to the shifter linkage or how it detects when the shifter is moving to a lower gear or what it perceived to be a lower gear shifting into neutral and moving the shifter towards the driver?

Smokey Nagata

The unsettling of the rpms is not as apparent or as obvious as intending to move down from 5th to 4th and getting to close to the 2nd gear gate !! and having the rpms shoot up way above your intended gear selection. It will get it close but will buck around what is technically ideal, unsettling the car and making downshifting feel like crap with the feature turned on.

Spooler

Sound like you are bumping the strain gauge and causing it to rev up. You need to shift faster and be more accurate with your shifts.

Smokey Nagata

I driven the car for multiple years now and have never had this issue(outside of the previous frustrating spat), I shift plenty fast and have raced/track the car !! I'm not sure shifting "slow" is my issue, especially downshifting since SRM is supposed to hold the rpms at the ideal range. What I mean is that the feature worked perfectly until very recently when I turned it off & then turned it back on, but thank you for your insight

Spooler

You may not have a SRM issue at all. It may be a misfire related problem.

Smokey Nagata

For instance Spooler after leaving work yesterday evening and into this morning the feature has worked correctly, Im just hoping for the best at this point



~ SRM downshifts correctly without any fuss or inaccuracy
Never had a misfire code on this car only returning (Lean) catalyst codes(P2096/ P2098).............because I don't have any

But I will double check the ecu to see if anything has popped up, I realize that a very mild misfire in some cases may not be detected by the ecm/ecu.

Smokey Nagata

Just an update on this as I forgot to respond with my or should I say my shops findings:

A couple months after this was posted I started to have other more alarming issues with the car. Which began right after a high rpm 2nd gear downshift. Heavy vibration upon idle and accelerating, clutch engagement issues/odd pedal feel were just some of the more prominent issues present at the time (there was clearly something wrong with the car). I ran through my personal check-list of diagnosis. Checking all mounts trans/engine, linkages, inspected driveshaft for excess play, scanned for codes, I suspected that my CSC was failing due to the clutch related symptoms. Everything checked out so I ended up bringing her in to RZG. They discovered that my stock dual-mass flywheel was coming apart (separating at the bearing area causing excess play) and the csc basically fell apart upon removal of the transmission. Good thing I purchased an entire clutch kit/w Tilton HD CSC the week prior to replace any parts that may have failed or needed replacing. The stock flywheel was the culprit. I replaced all other clutch parts while the tranny was out of the car.

cv129

Thx for sharing, good to know

__________________
Setrab | RE-71 | SPL | JRZ | Nismo | ARK | Whiteline | RacingBrake | CJM Oil Pan | Ti shield