Samurai 1.6 fuel pump wiring

[Larry]

Hi all,

I've had to fit an electric fuel pump as my 1.6 8v has no mechanical pump.

I've stolen an ignition live that I think was spare after removing the old aisin carb. Runs great as it is...

However, it's not ideal that the pump stays going in the event of a crash where the engine might cut out but the ignition could be left on.

Is there a simple way to get an live that is only live when the engine is running? From the coil or the oil pressure switch maybe?

What have others done?

Thanks

[Larry]

So having done some more reading, I think taking a "T" off the 12v feed from the instrument cluster to the oil pressure switch might work. I'll use this to trigger a relay to power the fuel pump.

I'll then either
A) package a non return valve on the fuel line

B) add a push button primer
or

C) fit a timer relay to prime the pump thats triggered by ignition live. Similar to glow plugs on a diesel.

Any better ideas, please let me know!

[Jordi]

If its a self priming pump shouldn’t need a priming switch.

When the engine turns over to start and the oil pressure builds the pump should kick in.

[Larry]

Thanks Jordi, that's a fair point, I'm not sure exactly hoe the pump works but judging by the in line filter between the pump and the carb it doesn't appear to drain back, so I should just try without first and see how I get on

[Anton]

Thinking about it, your solution would have the added benefit of saving your engine if you crack your oil pan or kill your oil pump. It's a pretty good idea.

[Jordi]

The instructions for most electric pumps have them wired via the oil pressure switch for safety.

[Larry]

Anton, I thought so too! A nice safety net

Jordi, that's interesting, mine didn't come with instructions but it makes sense.

[Anton]

I don't remember my pump having instructions either. It was a facet pump, so maybe it did and I just did the typical bloke thing and ignored everything in the box but the pump...

[Larry]

Just an update on this..

So I did try to wire it via the existing oil pressure sensor but it's only a single pin sensor. By the looks of it you need a 2 or 3 pin sensor so that one pin can illuminate the low pressure warning light when the ignition is on or when there is genuinely low pressure whilst running. And the other pin needs to power the fuel pump relay when there is oil pressure. So for now it's still wired via the spare 12v feed from the old carb. I just need to find the correct sensor as they can be either normally open or closed depending on how the vehicles circuit is wired.

[ScottieJ]

Mine's was wired up to an ignition live for years, I chose to just not crash my Sj