Hi,

I see you are getting the best information on your car from those who have more experience with the K-Jet system.
In the beginning I said as I remember! Well now! That now appears to be totally bogus!
I don’t remember anything! I remember my 1984 better but knew it was not the same.
Oh! How much different it really is.
Come to think of it, I have not ever had to deal with a fuel pump relay on my 1978 GT.

To Art and CB, thanks for the bail out of the “He doesn’t know what he is talking about, jail!”

To mike!
A ten ampere switch is a little over kill but it will not hurt a thing to use it.
That is, if, In thinking like most Americans, bigger is always better! :-).
It’s just larger than needed when you are trying to be inconspicuous.
Personally, I would not put it anywhere near the ignition switch as most people see enough movies to think that is the place to go, to to bypass your key, they don’t have!
I thought steering locks were suppose to stop that but I guess not?

I understand the reasoning for wanting it close by.
Why hassle yourself more than the crook or an unauthorized person, who wants to use your car, just because it’s there, not being used.
Nothing like having a 14 year old in the neighborhood that just might take that old car for a joy ride in a field someplace.
We were all teenagers once!

I had momentary thoughts for sometime after my last post and realized I didn’t answer your question about which of the two systems would be best to shut off.
Art, brings up his choices and combined them with his junction spot.
He knows his stuff and great pictures.

I did not explain why shutting down the fuel pumps would be best!
My logic and maybe his, is on any engine you don’t want raw fuel getting dumped into the cylinders. This washes down any oil on the cylinder walls and drips down past the rings to dilute the oil in the sump.
This happens because the flap is raised by the air flow from cranking.
The fuel distributor opens slots to ALL the injectors at once. These will pop open up under the fuel pump pressure supply.
That’s where the term Continuous Injection System - CIS comes from.
On a really cold engine it will get another dose from the cold start, thermally controlled, injector.

The move to the LH was to still do the same thing but only in pairs electronically.
In theory, this was to conserve fuel or possible waste during a cold start. The cold start injector was later completely removed too!
By using an electronic pulse width time, starting ahead of the valve actually opening, as before!
It came out to be almost the same.
Otherwise, there is not enough time to mix enough fuel into the amount of air needed for a cylinder in time at higher speed. We are probably talking about in a neighborhood of X nano seconds.

This brings me back to calling the computer in the kick panel an ECU. Even with what said CB about it NOT being a full blown ECU it is technically not true IMHO.
It is at least half that of one. It is a Lambda (translated to mean “perfect”) mixture computer working with an oxygen sensor signal. It electronically controls a frequency valve on the K-jet. This valve is a mechanical dump device. It sends gasoline back to the fuel tank to get what the LH does by not issuing fuel in the first place by less pluse width.

The LH system was built on the back of the K-Jet which IMO gained almost nothing except to get ether emissions during warmup and some fuel saving during a cold start.
The LH ECU just has more to process because of added details.
The LH is also better, after several years of tweaking, adding more sensors and opening up areas of programming to handle the changing engine conditions.
This ALL, In the search of the holy grail of perfection, which does not and cannot exist IMO.
Our brains drive this passion onwards.

This is why, after 125 years, we are still playing with the internal combustion piston engines of today!

Personally it’s been a good ride but the end maybe in sight!
There will always be “in someone’s mind” to try to keep the “Pursuit of perfection” alive!
We shall or must move on .... electronically and with a form of electricity management only!we need to discover the limits of both, of which are very tantalizing!

The pearls of the world are still awaiting discovery!

I applaud your efforts to create a kill switch for yourself. It will be where you want it and how you want to operate it.
This project is a great confidence builder to discover the many opportunities to make you grow and expand the world you live in.

Phil