Original 914/6 engine management, A couple of questions Options

[michel richard]

Please let me know if I have this right:

1) Original /6 cars came with Porsche's electronic ignition module of the time i.e. the BZK module, as opposed to only super-basic Kettering (sp?) points.

2) Fuel was carbs, of course, but there was an additional cranking enrichment which necessitated a thermotime switch, a "dashpot" on the throttle somewhere and perhaps a couple of other electrical widgets.

I'm trying to make sense of the engine wiring harness that I have, which is from a /6.

Thank you.

Michel

[Root_Werks]

As far as I remember, the 914-6 used the simple 3 pin CD box as the same year 911's did.

Carbs - yup and I think they had the electronic cut off attatched to them. But don't quote me on that one. (IMG:style_emoticons/default/idea.gif)

[GeorgeRud]

Yeah, there was a dashpot that attached a rod to the throttle linkage and used vaccuum from the intake manifolds. I believe that it shut off the gas on deceleration if I remember correctly, you probably won't find any cars actually using this feature these days.

Porsche calls this a vacuum box in their parts book (901.113.309.00), and it appears to have two wires connected to it.

The other sensors, etc. are pretty much the same as an early 911 engine. Good Luck!

[DonTraver]

The cold start enrichment was a disaster waiting to happen. It was two 2-3mm pipes with hole drilled in them that dumped raw gas into the intakes of each velocity stack. The pipes were mounted in the orginal air filter housing, controled by a valve over above the #3 cylinder. Didn't work very well, and was known to start engine fires. I still have the system, but it was taken off shortly after I bought my 6 from my step dad. Without it, I have to give them engine a couple of minutes to get the cylinder temps up before driving off.

Later, Don

[michel richard]

Don,

You mean the system was designed to dump fuel down the carbs even after cranking ? Yikes.

Thanks for the info, gentlemen, this will give me more confidence as I wire my engine compartment.

Cheers,

Michel

[gms]

I put together a schematic of the engine wiring harness...hope this helps



Notes:
Numbers on the right are connector pin
The back-up switch wires are gray w/white strip
Based on european car

[Cap'n Krusty]

Don,

You mean the system was designed to dump fuel down the carbs even after cranking ? Yikes.

Thanks for the info, gentlemen, this will give me more confidence as I wire my engine compartment.

Cheers,

Michel

That's NOT true. It sprays ONLY while cranking, and then only for a limited amount of time(determined by the TTS). The Cap'n

[maxwelj]

I don't know if they had a service note or something on the coldstart, but mine was removed as part of one of the early scheduled maintenance procedures by the Porsche Service dept. in Germany. Must have been within the first 6 months of it's life.

[michel richard]

Don,

You mean the system was designed to dump fuel down the carbs even after cranking ? Yikes.

Thanks for the info, gentlemen, this will give me more confidence as I wire my engine compartment.

Cheers,

Michel

That's NOT true. It sprays ONLY while cranking, and then only for a limited amount of time(determined by the TTS). The Cap'n

Cap'n

That's what I initially thought, thank you.

Glen,

That's exactly what I needed.

Michel

[SLITS]

Glen,

I assume that to be a 914/6 engine harness using the 914/6 relay board.

It'll help me to as I am debating whether to use a /6 or /4 relay board with a 73.5 CIS motor.

[michel richard]

I have a /6 relay board, that I'm mounting on the firewall . . . I just hope the lengths work out. I may actually have a spare /6 board, but not sure.

Michel

[maitaiken]

I was working at Stoddard's back then and recall there being a TSB that told us to disconnect the control wire. The dash pot also was used to hold the throttle open for a couple of seconds on deceleration for emissions.
Ken...

[gms]

Glen,

I assume that to be a 914/6 engine harness using the 914/6 relay board.

It'll help me to as I am debating whether to use a /6 or /4 relay board with a 73.5 CIS motor.

Yes, that is what I mapped the schematic from

[michel richard]

I'm missing something.

There's no blue wire ! what's connected to the ignition light on the tach? And I believe that light is essential to get the alternator working, at startup.

Michel

[sixnotfour]

There's no blue wire ! what's connected to the ignition light on the tach? And I believe that light is essential to get the alternator working, at startup.

Your right, Its internal on the914/914-6 relay board.
if you delete the relay board you need a jumper.

[michel richard]

Thanks, one issue is that I don't have a good /6 wiring diagram. I have now it figured out.

Michel

[Carl]

Don,

You mean the system was designed to dump fuel down the carbs even after cranking ? Yikes.

Thanks for the info, gentlemen, this will give me more confidence as I wire my engine compartment.

Cheers,

Michel

That's NOT true. It sprays ONLY while cranking, and then only for a limited amount of time(determined by the TTS). The Cap'n

Unless it doesn't. Ask me how I know. (IMG:style_emoticons/default/ohmy.gif)