Advanced Engineering Tech - How can I convert my 24x cps to read 3ppr




Snyper
10-20-2010, 12:38 AM
Im trying to get my factory Nissan tach to work and it works the same way as an LS1 tach. signal. The factory LS1 runs off of a "4 cylinder" 4 pulse per revolution signal and the factory nissan tach runs the same way only its a 6 cylinder so it runs off of a 3ppr signal. I know theres a way to get the 24x crankshaft position sensor to read 3ppm if its able to be divided by 8 some how.(Hinson supercars sent me a failed attempt at one of these and the instructions were to hook up a wire to the cps then into my nissan ecu and the unit used a power/ground to power it)

...Does anyone in here have the electronic ability to make a unit that would be able to read the cps/8 to give me the correct ppr to get my tach to work? Ive contacted MSD and a few other places with no luck.


Pocket
10-22-2010, 08:17 AM
Dont change anything related to the crank sensor circuit. The PCM is either set for 24x or 58x and is not adjustable in any way. If a 24x PCM does not receive a 24x signal, your engine will not run at all

However, your tach output value IS adjustable, talk to your tuner

Schwanke Engines
10-22-2010, 08:56 AM
what PCM are you using? You should be able to set up the tach output to whatever you want with EFI Live. We are a dealer if you are interested in purchasing it.


Snyper
10-22-2010, 10:47 PM
I am my tuner. And im using HP tuners. I tried to set it up as a V6 tach and it didn't work.

Snyper
10-22-2010, 10:48 PM
Does anyone know the voltage the tach signal puts out? Maybe that will help. The nissan signal puts out .1-.4v signal and I have to hook it into the #1 coil wire that goes into the nissan ecu to be translated by the CAN network and sent to the tach.

Pocket
10-23-2010, 08:24 AM
Try the booster wire if your output is correct but the tach still doesnt move

Snyper
10-23-2010, 12:13 PM
Booster wire?

salemetro
10-23-2010, 01:32 PM
You might PM CalEditor. He's pretty damned knowledgable, and might be able to help you out. He's in the middle of "scaling" my PCM's fuel gauge output for me, so I can use an '02 PCM to feed the fuel guage in my '98 cluster...a HUGE pain....and definitely NOT a regular "segment swap" to make it work. He's been great to deal with. He probably won't ask you for any $$$, but I'd strongly suggest that you make a donation to his cause in the form of $$$....there are not many people out there that are willing to tackle this kind of stuff.

Just my $.02

Pocket
10-23-2010, 04:02 PM
http://www.lt1swap.com/lsx_tach.htm

You need to bookmark and read over that guy's whole site before you start messing with wiring

Snyper
10-24-2010, 04:28 PM
Ive already wired up the whole car. Everything except the factory Nissan tach works. The Tach doens't get a tradition signal like most other tachs. The signal is sent to a control module then converted into a digital code which is then sent to the gauge.

This is from the FSM

http://i41.photobucket.com/albums/e266/Transam6383/Turbo%20build/Tach.png

I have to somehow figure out how to get a signal and attach it to the #1 ignition wire and thats how someone is the past has gotten it to work. However trying to get a hold of him has proved completely useless.

Snyper
10-24-2010, 05:22 PM
It seems like if I can get the LS coil signal 5v signal to match what the nissan ECU is looking for that it would work....

salsee
02-20-2011, 09:35 PM
Snyper,

Did you ever get this figured out and get your tach working? I am in the same dilema now with my G. Any help you can offer would be greatly appreciated.