My retarded car had a DOHC swap done and the tach isn’t working. I switched the SOHC cluster for a DOHC one but it still didn’t work. I’m thinking, alright, the new cluster is probably working.
Then I got a SAFC 2 wired up and thats also not reading a tach signal even though its hooked directly into the ECU.
I know the tach signal comes from the dizzy or something. Whats a realatively simple way to check to see if the wiring to the dizzy is screwed and how do I fix it? Keep in mind that I’m weaksauce with the wiring. Thanks.
Unfortunately I cannot tell you where the RPM signal is taken from. Just that its my understanding that the 2-pin plug on the diff gives an ABS signal…
Did I sell you a VLSD? if I did, it was non-ABS IIRC
Okay, so I was screwing around with the tach trying to get it to work. The signal is coming through to the ECU. When I put the tested on the tach wire that goes to the ECU, the voltage was raising when I revved the engine like its supposed to.
I was thinking that maybe the tach was just broken but it seems like this isn’t the case. The SAFC 2 isn’t reading anything for the RPMs. One thing I did notice is that it is getting a signal for Inst1 and that seems to be the RPM.
are you sure you connected all the same coloured wires at the body harness connector when you did the SOHC to DOHC swap? one of those is the tach wire so if you didn’t connect it then your tach won’t work.
the tach signal should come from the ignition coil.
if you’re sure that everything is in order then pull out your cluster and try to find the tach wire behind it, it will probably be the same colour as it is by the ECU. measure this wire and make sure it has the correct signal. if it does then your cluster is probably the problem.
From what I understand of the nissan timing/distribution system. The tach signal is a square wave pattern, which is read from a holofex disc in the distributer/CAS which has two rings, one has 360 holes, the other 4(or 5)
Are you sure you are getting the tach out signal from the correct wire on the ecu ? if it’s an increase in voltage, I would suspect that what you assume to be tach may be tps. double check the pinouts, the diagrams are difficult to read and you may have the wrong wires.
I have not directly checked the signal at the back of my tach but I will. The thing is, I thought that even if the tach wiring is screwed up, the SAFC 2 would get a signal since it is connected directly to the ECU. There is a value coming through the red/yellow wire which is the tach signal and this wire is connected directly to the ECU. Also, when my friend looked at the S13 wiring diagram, he said that if the fuel gauge signal is coming through, then the tach signal is also coming through.
Oh, and I just checked the SAFC2 manual and its actually In-1 I was refering to and its not the tach signal, its actually the airflow signal.
the fuel signal doesn’t come through the body harness connector as i remember, the tach, speedo, oil pressure light, engine temp and i think one more thing that has slipped my mind does too, but i’m sure its something with the engine, not the fuel level.