I am figuring out my /6 wiring and can not find the diagrams for the following items:
RPM sensor
RPM transducer
Radio noise supressor

Can I use the regulator on the /4 board?

All of these were originally on the console in the back of the 911. I am keeping the CIS if that matters. Do I need to keep these items? How did you/would you do it?

Thanks

first thing i'd check is to see if the alternator from the 911 is an internally regulated one; somewhere in the SC days they made that change. if that'd the case, you don't need either regulator, and i'm not quite sure what you do for the front alternator light (Terminal #61?). (i'm replacing my alternator with an internally regulated one and i need the answer to that question too...)

the radio suppressor - IIRC the original /6 had that too, so you should be able to find it on the /6 wiring diagram - you have the Art Zapf 914.6 digram, yes? well worth the money.

the other parts have names similar to the early MFI cars - one was the tach adapter, a ballast used to create enough current thatthe original Kettering tach could be used after the change to CDI. (Root-Works just went through that process and there was a thread not that long ago...) the other was a part used to control the overrun cutoff solenoid (specifically, it was to release it when the rpm dropped under 1500 rpm.)

the CIS cars use a clock (tach...) triggered fuel pump relay, so you'll need to provide an ignition signal to either that relay or the CIS mini-brain, whichever you have for your year car.

the last time i did an engine transplant between two CIS cars i pretty much needed the wiring diagrams of both cars to see what needed to match up with what.

good luck !

Don't do anything just based on this post, but I believe that if you use an internally regulated alternator, you don't need the relay board anymore, you can just plug the two plugs together. (unless of course you're going with MFI) At least, I believe that 's what Marc André Morin did when he put a 3.0 in his car.

Michel Richard
914/6 2.2E MFI

Thanks for the response, guys. I have yet to find a "mini brain" for my CIS. Where is it? I just have the CDI box, and the little doodads that I mentioned.

I have an externally regulated alt. I removed the whole deal from a '74 911. I will keep the relay board from the /4 because it will make the wiring for the reverse lights, brake lights, fuel pump, and the warm up relay (I will use the rear window relay for this). The 911 book that I have doesn't list the stuff that I mentioned, but I have a factory /6 wiring manual that I will consult if it has it in there.


I'll have more later. Again, thanks!

QUOTE (Dr Evil @ May 11 2005, 05:07 PM)

I have yet to find a "mini brain" for my CIS. Where is it?...I removed the whole deal from a '74 911.

aha. '74. no oxygen sensor?

then no frequency valve, and no mini-brain. end of problem.

the very early CIS systems were very simple. then they kept sprouting warts and band-aids in attempt to make them a little cleaner, or a little smoother, or idle a little better, and every little widget they threw at it caused two new problems...

QUOTE (Dr Evil @ May 11 2005, 01:44 AM)

I am figuring out my /6 wiring and can not find the diagrams for the following items: RPM sensor RPM transducer Radio noise supressor Can I use the regulator on the /4 board? All of these were originally on the console in the back of the 911. I am keeping the CIS if that matters. Do I need to keep these items? How did you/would you do it? Thanks

All that stuff is mounted on the /6 relay board. You either learn to live without it, or find a /6 relay board and the sensors. I did the latter. If you do that, you have to wire an adapter from the /4 harness to the /6 relay board. The factory made these for the 72 /6, but they are like hens teeth, impossible to find.

I Know that Jon Lowe had the wiring diagram for one of the adapters,but I don't have any contact info for him anymore.

Or you can do what I did, rewire the harness to match the relay board.

QUOTE (ClayPerrine @ May 12 2005, 04:29 AM)

Or you can do what I did, rewire the harness to match the relay board.

That's pretty much what I did, except I adapted a relay board from a 911 that had the MFI stuff and made a bracket to mount it in the stock 914 location.

Thats what I am gonna do. I should not be too difficult to adapt a /4 board. I can change the internals any way I want.

QUOTE (Dr Evil @ May 12 2005, 09:29 AM)

Thats what I am gonna do. I should not be too difficult to adapt a /4 board. I can change the internals any way I want.

There is no place on the /4 board for the tach adapter or the decel relay. You would have to make a custom harness location for them.

You are better off with a 911 relay board or the /6 board.

There is plenty of room on the bottom of the /4 board. I could maybe make a bracket that would secure everything underneath, and then hard wire plugs to all of the pieces. No extra harness required.

Its all speculation as I can not find my 911 board now When I get it and see what I am doing I am sure I will have more clarity. Thanks for the info.

Yo Doc - are you going to be using a factory /6 tach?

if not, you may or may not need the factory tach adapter (probably not, depends a bit on your ignition system...)

do CIS cars have a decel relay? i don't think so - i think that's an MFI-only thing...

QUOTE

the radio suppressor - IIRC the original /6 had that too, so you should be able to find it on the /6 wiring diagram - you have the Art Zapf 914.6 digram, yes? well worth the money.

Is Art Zapf around? I tried to email him. I bought his color diagram for the six. love it. i had it scanned. printed @ 2x the size. the scan is in jped and tiff. But I don't want to violate a copyright.

QUOTE (jfort @ May 12 2005, 03:14 PM)

Is Art Zapf around?  I tried to email him.

Recent 914.6 Diagram Thread