TheSnail
02-23-2009, 11:41 PM
Ok, I got this super wierd speedometer problem. I searched through 20 pages but found nothing on what I have. Maybe one of yall will know what went wrong. Basically, I got a 92 sentra with a sr20ve, had my original lsd and speed sensor. Everything was fine. I had a junk clutch so it killed its self along with my tranny within 8000miles. I bought a jdm tranny that was a open diff, an open diff axel and another one of these junk clutches. I swapped out the speed sensor from my previous lsd tranny, and put it in the jdm tranny since it was electric. Every thing was fine. Then the junk clutch proceded to kill its self along with the jdm tranny within 6000miles.
So after $1500 in stuff that these junk cluches destroyed, I bought a b13 ser tranny and an exeedy clutch, and use the same speed sensor as all my other trannies. This time around, I pulled the motor out the car to do everything nice an neat. While at it I pulled out the interior to get the sound deadening and firewall mat out, then put all the interior back in esentially to drop 50lbs with out anyone knowing. Put the motor back in, crank it up and I dont hear any clattering from the clutch like my last junk clutches which is good.
I did notice my speedometer shot up to 100mph and is going awire. The speedo at idle or with the car turned off will sit at 40mph, you go in reverse and it will hit 0mph and bounce from 0-60ish. Driving it, the speedo would fluctuate sparatically saying you're going anywhere from 0-80 in first. At highway speeds, it becomes more linear, and bounces +/-10mph, saying youre going about 120-130mph if youre going 60, and pinning the gauge past 150 if your going 80. Also I noticed light clicking noised from around the dimmer switch/gauge cluster area. I figure this is a relay poping. I also figured that I might of left something unpluged, and that the speedo was not on my priority list untill I have time to fix it.
This is where it becomes weirder. So I unplug the cable at the speed sensor, to not see the speedo going crazy and I took the car for a spin. I dont gun it since I needed to waste all the stale gas and break in the clutch. Once I ran out of gas, I got some fresh 93, and drove it about 10miles before gunning it. My chipped VE ecu has a rev cut at 8500rpm, but when I gunned it, it hit a rev cut at 6800 rpm, which is not even the stock ve ecu's 7200 far aswell my 8500rpm chipped one. I gun it some more, but nothing helps. I figured since its been down for 4months, and I set my air/fuel to 13.6:1 where it made the most power in 70+deg weather, that with it now being 40is deg it may of condensed the air, and leaned the car out, making a 6800rpm fuel cut kind of thing. So I bumped up the a/f but still had the 6800rev cut.
The next day I looked into it more, connected the o2 which does not matter, since my ecu runs on a closed loop system, taking no signal from the o2. Then, I disconected the battery ground to reset the ecu to maybe learn the speedo signal. Then I check the oil level. It was a quart low, so I put two an two together, and figured my ecu is tuned for the high lift cams that are activated by the solinoids which are activated by oil pressure. With oil pressure being low vvl was not kicking in, while my ecu thought it was, causing the rev cut from being way out of tune. I took it for a spin, and it everything was back to normal, reved to 8500 happily. So now Im happy, but my speedo is still out of wack. So today, I was messing with it, and disconnected the speedo cable from the speed sensor, since I didnt want it to be staining the speedometer and get it uncalibrated. I took it for a spin, gunned it and hit a 6800rpm rev limit. I was like I cant be burning/losing oil that fast (50miles), so I put two and two together, pulled off the road and connected the cable back to the speed sensor. Went and gunned it and it reved to 8500 rpm no problem. So now im confused, why would the speed sensor have an impact on my ecu's rev cut expecially when my ecu has speed cut removed. By looking at it, the speedometer is getting signals from something more on the lines of nor timing, o2, or tps. Something is not right, and I dont want the signal from the speed sensor, to be telling the ecu that the timing or whatever is so 'n' so and my engine goes boom. I did f-up the dimmer switch by breaking the board pulling out the plug, but the gauge lights still work, and that would not send a signal to the ecu right? Also the speed sensor gear on the tranny I got is blue, and im dont remeber the color of the speed sensor from my 92 ser lsd tranny thats in it right now, but I think they come in purple, green and blue. Basically what I'm asking is are there differences in mechanical speed sensor teeths/ratios for a b13? Even so, why would a speed signal affect the ecu's rev cut? Im quite stumped, so if anyone that knows whats wrong or can figure it out I'll send them $8 paypal. I know thats a sorry amount but I got $9 in my paypal lol. Though if they have a b13, I'll send them one of those b13 cubby gauge pods that I make aswell.
Thanks, Snail
So after $1500 in stuff that these junk cluches destroyed, I bought a b13 ser tranny and an exeedy clutch, and use the same speed sensor as all my other trannies. This time around, I pulled the motor out the car to do everything nice an neat. While at it I pulled out the interior to get the sound deadening and firewall mat out, then put all the interior back in esentially to drop 50lbs with out anyone knowing. Put the motor back in, crank it up and I dont hear any clattering from the clutch like my last junk clutches which is good.
I did notice my speedometer shot up to 100mph and is going awire. The speedo at idle or with the car turned off will sit at 40mph, you go in reverse and it will hit 0mph and bounce from 0-60ish. Driving it, the speedo would fluctuate sparatically saying you're going anywhere from 0-80 in first. At highway speeds, it becomes more linear, and bounces +/-10mph, saying youre going about 120-130mph if youre going 60, and pinning the gauge past 150 if your going 80. Also I noticed light clicking noised from around the dimmer switch/gauge cluster area. I figure this is a relay poping. I also figured that I might of left something unpluged, and that the speedo was not on my priority list untill I have time to fix it.
This is where it becomes weirder. So I unplug the cable at the speed sensor, to not see the speedo going crazy and I took the car for a spin. I dont gun it since I needed to waste all the stale gas and break in the clutch. Once I ran out of gas, I got some fresh 93, and drove it about 10miles before gunning it. My chipped VE ecu has a rev cut at 8500rpm, but when I gunned it, it hit a rev cut at 6800 rpm, which is not even the stock ve ecu's 7200 far aswell my 8500rpm chipped one. I gun it some more, but nothing helps. I figured since its been down for 4months, and I set my air/fuel to 13.6:1 where it made the most power in 70+deg weather, that with it now being 40is deg it may of condensed the air, and leaned the car out, making a 6800rpm fuel cut kind of thing. So I bumped up the a/f but still had the 6800rev cut.
The next day I looked into it more, connected the o2 which does not matter, since my ecu runs on a closed loop system, taking no signal from the o2. Then, I disconected the battery ground to reset the ecu to maybe learn the speedo signal. Then I check the oil level. It was a quart low, so I put two an two together, and figured my ecu is tuned for the high lift cams that are activated by the solinoids which are activated by oil pressure. With oil pressure being low vvl was not kicking in, while my ecu thought it was, causing the rev cut from being way out of tune. I took it for a spin, and it everything was back to normal, reved to 8500 happily. So now Im happy, but my speedo is still out of wack. So today, I was messing with it, and disconnected the speedo cable from the speed sensor, since I didnt want it to be staining the speedometer and get it uncalibrated. I took it for a spin, gunned it and hit a 6800rpm rev limit. I was like I cant be burning/losing oil that fast (50miles), so I put two and two together, pulled off the road and connected the cable back to the speed sensor. Went and gunned it and it reved to 8500 rpm no problem. So now im confused, why would the speed sensor have an impact on my ecu's rev cut expecially when my ecu has speed cut removed. By looking at it, the speedometer is getting signals from something more on the lines of nor timing, o2, or tps. Something is not right, and I dont want the signal from the speed sensor, to be telling the ecu that the timing or whatever is so 'n' so and my engine goes boom. I did f-up the dimmer switch by breaking the board pulling out the plug, but the gauge lights still work, and that would not send a signal to the ecu right? Also the speed sensor gear on the tranny I got is blue, and im dont remeber the color of the speed sensor from my 92 ser lsd tranny thats in it right now, but I think they come in purple, green and blue. Basically what I'm asking is are there differences in mechanical speed sensor teeths/ratios for a b13? Even so, why would a speed signal affect the ecu's rev cut? Im quite stumped, so if anyone that knows whats wrong or can figure it out I'll send them $8 paypal. I know thats a sorry amount but I got $9 in my paypal lol. Though if they have a b13, I'll send them one of those b13 cubby gauge pods that I make aswell.
Thanks, Snail