Need your help Options

[mlindner]

So my 1974 914-6 GT Tribute has been running great for the last five years. But..last month I purchased a 1971 911 E tach for the tribute. I am running the 2.2L six with MSD off of the 4 cylinder tach with Adapt a Tach and all was good. So two days ago I thought I'd switch out the tach so everything would look complete. WRONG, I pulled the Adapt a Tack, put the 12v on the new tach, coil wire or MSD to tach and then ground. All this with kill switch off. When put on, fuel pump sound good, start engine good, oil pressure good but tach not moving. So recheck everything and try again, engine starts but now no fuel pump sound or lights, no pressure gauge single. Turn off, must have been running on fuel in the PMOs. Checked all fuses OK,pulled the whole gauge set up out, can't see any ground wires off. I get it if I bought a bad tach, but now I can't drive the car. And my biggest problem is I'm pretty color blind when it comes to auto wiring. When all this was started five years ago my good friend from Florida came up to WI in the middle of winter to help me install and wire (Not my skill level). Tracing wires and currents don't have a clue. The cars wiring harness is all stock, only thing new is Perry Kiehls engine harness and Kill switch to MSD box. Thoughts. Mark

[fixer34]

Isn't there something different about the -4 tach and the 914-6/911 with the CD box?

Don't recall the specifics, but I thought there have been threads about it.

You broke one of the cardinal rules of cars, computers, etc.
"Don't monkey with a working machine..."

[sixnotfour]

That tach wont run off msd..needs an adapter.. find instruction for tach adapt..

[infraredcalvin]

That tach wont run off msd..needs an adapter.. find instruction for tach adapt..

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Can you put it all back and confirm everything working?

[porschetub]

That tach wont run off msd..needs an adapter.. find instruction for tach adapt..

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Can you put it all back and confirm everything working?

not a bad idea but if the tach adaptor is set for a 4 cylinder which it has to be it will need the reset to correct pulse rates for 6 early tach,these switches on 1 & 5 should do it and pull the 2 pin black jumper in ensure a high voltage pulse which from memory are the same for both 4 & 6 early tachs so it most likely been unplugged already.
Plug it back in and make sure the LED lights up when the engine is running ,I ran the Ashlock unit and it worked great until the tach died ,just got pissed off will old parts so purchased Ashlock new tech driverboard for my 73 911 tach and now know I have no future issues and it works great .

[Retroracer]

Mark - your description of the connection sequence is a bit unclear - "coil wire or MSD to tach" - but is it possible you may have damaged the MSD unit by connecting it directly to the tach? I believe early 911 tachs were connected to the CDI / coil somehow using a pulse transformer (magnetic component) which you didn't mention if you added.

Perhaps your MSD unit is fused separately (installation instructions encourage this), an inline fuse that isn't in the 914 fuse panel? Or even fused on the 914 relay board (if you still have one and depends how the MSD was wired)?

More explicit pics / info / wiring diagram might be good....?

- Tony

[cgnj]

I read this post 3 times. I'm confused. This is what I understand.

1. The car is currently running.
2. The fuel pump does not run.
3. Tach is inop
4. Lights not working. Running lights, gauge warning lights, gauge illumination lights or all of them?
5. Is there a Permatune and MSD in this setup?

I don't know if this link will help but I found it on the Bird board.
Pematune MSD tach adaptor