S-AFC Neo not showing RPMs!

[DallasN2O]

I have read the vfaq and the wiring diagram that comes with the neo. They point to two entirely different wires for the rpm wire. I have tried both wires and can not get the neo to display rpms. It just stays at zero. I have tried changing number of cylinders and all that. No luck. My car is a 90 model Laser.. is there a special place I need to tap into to get an RPM signal to the afc? Somone please help me.

 

[DallasN2O]

What if I ran the green wire from the afc and tapped into one of the wires on the power transistor? Anyone know which wire would work?

 

[DallasN2O]

I know I'm not supposed to bump but I really need help on this guys please?

 

[Siral3x]

AHhh...I don't have a wiring diagram infront of me but I think it's the white wire on the coil pack on the 90 models is the tach signal wire. Not the wire with the white stripe...the WHITE wire

 

[DallasN2O]

So is that the only way i can get an rpm signal is wiring into the coil? Ive tried 4 different wires on the ecu harness and cant get it to read anything at all. 4th wire from the left, 4th from right, and even 2 others on the middle plug. I'm so frustrated.

 

[DallasN2O]

Ok looking at the vfaq 1g ecu pinout diagram... I have hooked the green afc rpm wire to the following wires:

21,16,54,56, and 109 (I believe 109 is the same white wire as on the coil)

I haven't gotten the rpm gauge on the afc to move at all. I have tried changing num of cyls to every different setting. I am extremely frustrated as I paid lots of money for all this crap and something so stupid as this keeps me from making progress. Wisemen pls help me. Is there a test I can perform on the AFC to see if its defective?? Any other suggestions? Thanks.

 

[DallasN2O]

I'm still having this same problem.. I need to know if the AFC Neo is looking for an rpm signal that the 90 ignition system doesnt provide. I know the 90s are different than the rest of the 1g's. Have any of you installed a s-afc II or neo on a 90? Do I need some kind of signal translator? Please help.

 

[steve]

Like I asked in another thread.
Does your existing tach work?
What color was each of the wires you tapped into? Far too many people mix up the pin numbers since they don't understand what the diagrams are showing them.

 

[DallasN2O]

Yes the stock tach works fine. I know for sure I tapped into an all white, an all blue, and an all yellow. I was attempting to tap into the black wire directly from the CAS last night and broke the wires coming out of the bottom of my old 90 CAS. I guess now I'll try and put my blacktop CAS on it and try to find a signal to tap into there.

 

[steve]

The point of me asking was to make sure you have the right pins. If you don't want the help...

 

[DallasN2O]

What? What gave you the idea I don't want the help? I was just telling you what colors the wires were by memory bc I'm at work away from the car.

 

[steve]

Thank you.

Since your the eyes and ears for me I need you to be as specific and precise as possible or I can't help because I can't answer the questions that lead to the next steps.

 

[DallasN2O]

ok. I just got through tapping directly into the black wire coming from the CAS and splicing it into the green wire on the s-afc neo. I just ran the wire through the passenger window for testing purposes.. I get absolutely no rpm reading at all. Not even a twich. The factory tach is working flawlessly. Is it possible that the optical signal isn't recognized by the s-afc? Would I have to switch to the hall-effect style CAS to make this work? How can I test to see if my neo could be not functioning correctly? If I put a volt meter on the black wire coming from the CAS, what should I see? I tried it and the voltage rose with rpms so it looks to me like that is the correct wire.

 

[DallasN2O]

Suggestions?

 

[gobagheera]

Hey, just saw this thread when I was searching for the RPM wire for my Zeitronix and noticed that you were getting nowhere.

Upon my research, you tap your green RPM wire from the AFC to pin 58 (white) on the ECU based on the Zeitronix install. No need to tap all the way from the coil. Hopefully this helps.

 

[steve]

Upon my research, you tap your green RPM wire from the AFC to pin 58 (white) on the ECU based on the Zeitronix install. No need to tap all the way from the coil. Hopefully this helps.

Pin 58 on a 2G is the same signal as pin 109 on a 91+ 1G. Both are the ignition pulses from the power transistor.

 

[xhackerekx]

buy older version safc .
neo just waste u time and money.

 

[DallasN2O]

Pin 58 on a 2G is the same signal as pin 109 on a 91+ 1G. Both are the ignition pulses from the power transistor.

5 years later... . So where should I tap into on a 90 car for rpm signal for S-AFC?

 

[hhuricane]

The easiest place for a tach signal is the tach connector on the firewall. It's where I get the signal for my shift light and no need to fart around with the ecu wiring.

 

[DallasN2O]

The easiest place for a tach signal is the tach connector on the firewall. It's where I get the signal for my shift light and no need to fart around with the ecu wiring.

ok so if I tried that and I failed to get a rpm reading on the afc then I must have had a defective unit... I sold this car to a friend a week ago and we are resuming the project so I'm trying to address this problem before we get back to it. We ordered an old school afc-II so I hope it works.