i figured out that more than likely, the jerkiness w/ my car's shifting lately is due to not only the addition of the intake, but also the fact that the speed sensor in my speedometer is broken, so (as the mechanic explained it) the transmission doesn't really 'know' how fast the car is going, and therefore is unable to shift smoothly and whatnot. while the guy didnt guarantee that fixing the speedometer will in turn fix the jerky shifting, he did say that however i look at it, the speedometer/odometer sensor is the next thing i need repaired if i want to fix other problems. my situation is this: the sensor part alone is about $125-150, and then whatever it would cost to get it all put in (he told me no more than 200 bucks total). should i go ahead and do this? obviously, not having a speedometer sucks in its own right, since i get even more nervous when i see cops and everything, and the jerkiness of my cars shifting is really annoying, and probably not all too good for the car. would you fix this if it happened to your car anyone? just looking for some input... thanks for your time

NICK

 

Did your jerky shifting start when the speedo broke?

 

no, it gradually worsened since the addition of the intake... i had been told that adding new hardware to an engine requires the ecu to 'learn' how to run properly w/ the new stuff (its been 2 wks) but i dunno... as i said before, the mechanic didnt guarantee that the speedo was responsible for the jerky shifting, but he did say that either way i look at it, that is the first thing i should fix if i want to troubleshoot other running problems; what he said that did make sense is that the car doesnt really know how fast i'm going, so it gets 'confused' w/ the shifting of each gear and whatnot... what do i know though. ill probably just end up fixing it regardless, but i sure do hope it does in fact fix this jerky shifting; what else could it be from? i just got 2500 bucks worth of new manifold studs, exhaust, and a bunch of other stuff engine related that i dont even fully understand.. anyone know anything that might help me out?

 

Listen to your mechanic, I think he's on track. What he's saying about the car not knowing how fast it's going makes total sense. Our cars rely heavily on information from so many sensors that it's very possible the tranny is confused at this point.

 

good lookin out man; the guy just called me to tell me he found a sensor for 100 bucks and he'll put it in for 'real cheap' (he better, considering i've paid his garage over 3Gs in the last month+) so it looks like ill get this **** fixed; i'll let everyone know if it fixed my shifting issue; thanks for the info anyone

 

I dont know much about the nissan 3 gen's but on my 4 gen, there was really only one speed sensor- and thats the speedometer pinion gear that goes into the transmission. IF (emphasis on IF) this part is the same/similar to what mine is, $100 is an absolute rip off. Even at my local dealer a new one is $20. In this pic, its that red thing.

 

damn, anyone know if these parts are similar in 3rd and 4th gens?

i have heard that the earlier 3rd gens didnt have a computer chip that controlled the speed/odometer (which mine does); if it broke it was easy to just have a shop fix it; when nissan started using 2 chips (one in the steering column and one behind the dash) that work together to operate the speed/odometer, it became much harder to repair faulty ones. anyone know anything further? i hope i'm not gettin ripped off by paying 100 for this part...i havent given the guy the goahead to get it just yet...help please

thanks
NICK

hey matt93se, you know everything about 3rd gens, wanna enlighten me as to what is goin on w/ my situation?

 

Jeff92Se should probably know about this... ask him.

 

Nick

If you pull the FSM, it should tell you how to test the speed sensor? Maybe this can help avoid unnecessary expense?