Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post

elpelon · 10-22-2016, 07:07 AM

Update : had to work 4 straight 12 hrs shifts last week, so I haven't had a chance to look at the car until yesterday. I took another test drive and confirmed that the ecu indicated speed was very erratic and 2 to 2 1/2 times the speed indicated by speedometer and also confirmed by GPS speedometer. I am convinced that the cutting out is due to the speed governor kicking in. After digging into various forums and my Chilton manual I arrived at the conclusion that there is a short or something between the speedo and the ecu. I also saw that there is a yellow wire with a green stripe running from the speedometer to the ecu and cutting it should solve the issue. Since I had the ecu cover off already and could see the wires and not really wanting to tear into the dash panel, I decided to clip it at the ecu. I quickly located a yellow /green wire. I snipped it and a cel came on. It was the evap canister.... Looking closer and blowing off some Dust, I saw about 6 more yellow /green wires... So don't do that. I reattached the clipped wires and put the ecu cover back on. I finally just removed the cluster and there was only one yellow /green wire. I clipped it. Test drive was flawless. Ecu indicated speed stayed at 0. The mpg and some other information functions no longer work, but that is a minor issue. I had already ordered an oxygen sensor and new plug wires, so I popped those on and she is humming along like a sewing machine. Smooth as butter. I am 90% convinced that she is cured. I also noticed that my indicated voltage stabilised at a normal 13.2-4 volts. I am wondering if the clipped wire was shorting out somewhere. The wiring that I saw all looked to be in really good condition, especially for a 21 yr old vehicle. Sorry for being so long winded, but I am a nurse and my documentation /charting habits are hard to suppress. As these cars age, electronic issues are going to pop up more frequently and I hope that this post is helpful to someone else in the future. I will post again here if the issue pops up again, but I am almost certain that it is resolved.

10-22-2016, 07:07 AM	#3
elpelon Join Date: May 2014 Location: Oklahoma Age: 58 Posts: 11 Trader Rating: (0)	Update : had to work 4 straight 12 hrs shifts last week, so I haven't had a chance to look at the car until yesterday. I took another test drive and confirmed that the ecu indicated speed was very erratic and 2 to 2 1/2 times the speed indicated by speedometer and also confirmed by GPS speedometer. I am convinced that the cutting out is due to the speed governor kicking in. After digging into various forums and my Chilton manual I arrived at the conclusion that there is a short or something between the speedo and the ecu. I also saw that there is a yellow wire with a green stripe running from the speedometer to the ecu and cutting it should solve the issue. Since I had the ecu cover off already and could see the wires and not really wanting to tear into the dash panel, I decided to clip it at the ecu. I quickly located a yellow /green wire. I snipped it and a cel came on. It was the evap canister.... Looking closer and blowing off some Dust, I saw about 6 more yellow /green wires... So don't do that. I reattached the clipped wires and put the ecu cover back on. I finally just removed the cluster and there was only one yellow /green wire. I clipped it. Test drive was flawless. Ecu indicated speed stayed at 0. The mpg and some other information functions no longer work, but that is a minor issue. I had already ordered an oxygen sensor and new plug wires, so I popped those on and she is humming along like a sewing machine. Smooth as butter. I am 90% convinced that she is cured. I also noticed that my indicated voltage stabilised at a normal 13.2-4 volts. I am wondering if the clipped wire was shorting out somewhere. The wiring that I saw all looked to be in really good condition, especially for a 21 yr old vehicle. Sorry for being so long winded, but I am a nurse and my documentation /charting habits are hard to suppress. As these cars age, electronic issues are going to pop up more frequently and I hope that this post is helpful to someone else in the future. I will post again here if the issue pops up again, but I am almost certain that it is resolved.