Fuel pump runs when I flash main beams?

[flux3d]

Yep, bit of a strange one. Everything is running perfectly, but I noticed the other day that, with the engine NOT running and the key turned to to position one (the point just before cranking the engine, and when the dials come alive) if I pull the stick towards me, flashing the main beams, the fuel pump runs/primes. This is with the light switch in the OFF position.

Is this normal, or just a oddity of my car? Maybe I've discovered a way to get the pump to prime every time. :wink:

[jawn101]

Yep, bit of a strange one. Everything is running perfectly, but I noticed the other day that, with the engine NOT running and the key turned to to position one (the point just before cranking the engine, and when the dials come alive) if I pull the stick towards me, flashing the main beams, the fuel pump runs/primes. This is with the light switch in the OFF position.

Is this normal, or just a oddity of my car? Maybe I've discovered a way to get the pump to prime every time. :wink:

I assume you have the original RPM relay. These are not terribly reliable or predictable as to what they will do. The voltage variation caused by flashing the lights in your car must be enough to convince it to prime.

If you get Dave's solid state one it will prime reliably every time.

[PB Co]

Sounds like a cool feature to me.

I am still working my way through my service manuals. What in the world would cause this? I can't say I've ever tried it.

[PB Co]

There ya go.

[DMCMW Dave]

Move the large bundle of wires at the back of the engine away from the ignition distributor.

[Bitsyncmaster]

Step on the gas and it will prime also if you don't have that cap on the idle switch. It's just getting a pulse on the ignition wire.

[Tillsy]

You've also got to watch out for low level ionic pulses ;)

[Flash66]

And Photon Torpedos! What a cool feature your car has. Flash the main beams to dump fuel and kick in the afterburner!

[dmc4087]

Mine does this too. I'll have a look at the wiring that Dave mentioned above.

[flux3d]

lol, it sure is a cool feature. I think I'll keep it as it is for the moment. Adds to the character a bit, without causing any problems..... I hope.

[DMCMW Dave]

The more common complaint is that "I hit the brakes, flash the lights or do some other high-current-draw function and the engine stumbles".

What is happening is that stray pulses are getting picked up by the pickup coil inside the distributor and it throws out an extra spark pulse or two. Simply moving the wiring bundle farther away from the distributor will cure it.

[KMC-DMC]

Yep, bit of a strange one. Everything is running perfectly, but I noticed the other day that, with the engine NOT running and the key turned to to position one (the point just before cranking the engine, and when the dials come alive) if I pull the stick towards me, flashing the main beams, the fuel pump runs/primes. This is with the light switch in the OFF position.

Is this normal, or just a oddity of my car? Maybe I've discovered a way to get the pump to prime every time. :wink:

I'm happy to read that it's not just my car that does this. I stripped back the loom a few months ago to find if there was a problem but I think it's just some sort of electrical emissions problem..