Running an aftermarket Tach....

[streeteg]

Already searched and I am new to Nissans so I dont understand some of the terminology----

I know the signal comes out of Pin 7 but I dont know what that means

Also I have heard the word CAS used a few times.... help a nissan newbie out...

Car is an RB25 Z

[s13point5]

you take the signal wire from the tach and you splice it into pin 7. but why do you need an aftermarket tach. your stock one should suffice

CAS = Cam/Crank angle sensor

[streeteg]

The car is a 74 Z with a custom Dash and an RB25 swap. Currently there is not stock tach and this will be my only. also +1 for a shiftlight...

Tomorrow I will be taking apart the dash and figuring out the wiring to the best of my ability.

Dumb questions but---- which one is pin 7 lol?

(FYI I have been working on cars for years I was just primarily into the Honda game--- so I can tell you anything that has to do with a B series but its going to take me a bit to warm up to the easy details of a Nissan....)

[s13point5]

pin 7 on a RB ecu would be the same pin 7 on a honda ECU theoretically. you just find a pin layout of an RB ecu. im sure i can look in the FSM when i get out to the garage and find it for you and post a picture. how do you know its pin 7 tho?

p.s. im a honda boy still at heart. ive owned 4 swapped EKs (i ONLY drive EKs haha) i still drive one as my beater/daily driver

[s13point5]

okay so i did a little research for you. i dont know where you got "pin 7" from but that pin is blank on the RB ecus. the pin you are looking for on the ecu is pin 35 and its yellow with a blue striped wire. i havent looked at my own RB ecu to confirm this yet but i think they are right. hope this helps.

[zdrifter]

If you go with an autometer tach you need to get a tach adapter and splice the tach adapter by cutting the white wire going to the ignitor and putting the adapter between the wire you just cut, install your gauge and make sure you have the wires cut for a six cyl.

[streeteg]

Thanks guys! I am going to attempt to do it today....

here is my old honda that I sold to get the Z....

[streeteg]

any news on the yellow with the blue striped wire? there is one coming out of my ecu that does not go to anything so I am tempted to try it...

[DJButton]

I'm jealous I should have kept my Honda for a daily...

[s13point5]

I'm jealous I should have kept my Honda for a daily...

stock motor currently averaging 38 mpg . she is gonna stay stock motor because i have the 240 as the "fast" car. i know not alot of people like hondas but i think my daily looks good

streeteg: dope EG hatch

[streeteg]

okay so i did a little research for you. i dont know where you got "pin 7" from but that pin is blank on the RB ecus. the pin you are looking for on the ecu is pin 35 and its yellow with a blue striped wire. i havent looked at my own RB ecu to confirm this yet but i think they are right. hope this helps.

that wire didnt work---where else can i draw a signal for the tach?

[streeteg]

Anyone? I still need a signal for the tach.....

[Sil240]

If you go under the hood, on the wire harness there is a little plastic cylinder with a cap (there's actually 2 of them, the one with the yellow wire/redstrip) But that wire shouldn't work if you have no pulse coming out of pin 7 on the ecu.

I'm in the same boat as you are.There is something messed up in your wire harness.

Mine did work but then it was re-wired to make the engine work but now no more tach signal. POOOOOP!!

[Darius]

Pin #7 is not blank on RB25 ECUs. Pin #7 is blank on the M63 plug on the RB harness, so maybe that's where you are confused. The tach signal wire runs from pin 7 on the ECU to pin 35 in the M63 plug. Yes it is Y/L (yellow w/blue stripe).

[SIL-LINE]

if you look at the ecu plug (looking at it from the side with all the wires sticking out )

from right to left there are three 20 prong slots and one 16 prong slot. on the side that has the 16-and 20 (from bolt to the left) the top row number four is your rpm signal.

see if this works , this is from my SAFC pin diagram so it should work out ...

good luck .....

[240wootie]

I have a '96 EK hatch i bought a few weeks ago, ZC swapped, carbon hood, einkei's, and real coilovers. not a bad daily driver. it was soooo freakin loud when i bought it. i had to drive 3 hours to get it home... i drove for 30 min, then stopped and got ear plugs, lol. its much better now. hope to get my rb20 coupe running here pretty soon... when i get time to sort out the wiring harness, lol.

[streeteg]

Wiring is just a big maze... I dont mind doing it but at least on a honda it utilized stock harnesses so it made tracing the wires that much easier. Not to mention I did not do this swap myself so having to go over anothers work is difficult. Either way I will try the suggested and hopefully get a signal soon. ...

Thanks for alll the help. if this doesnt work there will be pictures next to my questions on the next round