I have a 1.8L with duel 40 webers. It seems like the fuel pump is always running with just the key in and engine off. Is this correct or???

Thanks

only with the key on may wire to the coil we wire to where the fuel pump relay used to be for the original injection ala the 914-6 setup.

mine needs to have the ignition on (2nd click) and then mine will just stay on too. dual webers as well

Mine too.....2nd click, dual webers

HOW TO: run the fuel pump for carb conversions, the easy solution!

http://www.914world.com/bbs2/index.php?showtopic=25954

Andy

I think the original question was related to how this really works or
is supposed to work.

The mod in the Tech Article is very simple and runs the pump when ever the key is on,
regardless if whether the engine is actually running.

The factory circuit in the FI system monitored the distributor ignition to tell if the
engining was running. To long without sparks, and it shut down the fuel pump
as a safety feature.

In order to perform that function you need a circuit that monitors something
like oil pressure or the distributor.

It wouldn't be that hard to add in one of the off the shelf
fuel pump cutoff switches that uses oil pressure.
Or for a few bucks in parts for resistors, caps and a transistor, you
could monitor the distributor where it feeds the low side of the coil/tach
which would mimmick the factory behavior.

A quick and easy safety measure is to add an inertia switch that connects
the ground to the T4b connector. This way in the event of a collision, the
switch throws, disconnects the ground, and shuts down the fuel pump.

-------------

This seems to be coming up every now and then. Perhaps I should update
the Tech Article to explain this better and include some safety fuel pump cutoff
options????

--- bill

guess i misread the initial post ...
yes, with this mod the fuel pump will run until you turn off the key.

how about a flywheel sensor?
Andy

Actually, the CB pump comes with a pamphlet saying that there should be an oil pressure cutoff switch installed with the pump. Methinks nobody does this however.

I'll be re-doing my car this summer. I'll put together an update for the tech
article to include some safety options.

I had looked at this before sometime back.
I looked at some cutout switches from Summit & Jegs.
As I recall, it wasn't an easy direct drop in of the oil pressure cutouts
to connect them to the relay board T4b connector signal and use the
existing wiring.

There were some polarity issues which would require an extra relay or
transistor and in some cases you have to add some extra circuitry to enable the
pump while cranking the starter and to stretch out the signal to prevent accidental
cutouts during momentary loss of pressure or low pressure.

My preference from a simplicity and cost perspective is to handle it the same
way the factory did as it is the cheapest and easiest to install.
It taps the starter/start signal and monitors the tach signal and doesn't
require any additional sensors or plumbing into oil lines.
It could also be done by monitoring the oil pressure light signal instead
of the tach signal.
The circuit is very simple so the cost of the parts should be less than the
cost of an oil pressure cutout switch let alone the extras needed to plumb in
the switch and hook it into the existing wiring.

However, since most folks are not electrically inclined, I'll also show how to wire
up options with more generic off the shelf parts.

It may be a few months, but I will get to it.

--- bill

I sense next winter's project for me! Please don't forget us, Bill!

I've been around and around on this twice now. I first used an inertia cutoff (punp ran all the time when the key was on), but I kinda worried about it every now and then.

When the plastic bracket holding the cutoff to the car cracked, I took the opportunity to repalce it using my non-electrically inclined skills (I admire the IBEW guy who did my house -- a work of art!).

I used two relays, one Single Pole Single Throw realy and one Simgle Pole Double Throw relay. I'm sure there's a better way to do this and I can't wait to see it! Here's the diagram:



I also relocated the fuel pump to the front so it was easy to connecct to the oil light wire (before the oil light).

It works, and the pump won't run unless the oil light goes out.