SeanR

What some might be confusing with key on is the PSD pump priming its self in the later cars.

Mrmerlin

I have heard stories about these mysterious boxes being added to fuel injection systems to satisfy EPA regs, from the description this sounds like one of the those boxes that might do absolutely nothing except look like it does.
Your car also may not have had a O2 sensor in its system and this box may have been added to interface it, or be a fake interface that does nothing

Alan

Some years fuel pump relays do this as Porken says - most don't. The ones that do usually start a tad quicker (less cranks) when the fuel pressure has bled down.

Some older cars may not be using the correct fuel pump relay (or it may not be fully functional) the one that does the brief pre-run pressurization has 5 pins including a dedicated ground (31) terminal.

The headlight relationship - seems most likely to be via the dedicated ground - I'd clean and secure the above CE grounds to address this (obviously its not supposed to work this way)

Alan

PorKen

Hi to lo impedence injector converter? (Too complicated.)

Lopez

not that it matters to the OP, but my '78 CIS car most definitely runs the fuel pump for about 1 second with the ignition switched on before cranking the starter.

agen7seven

Ok it's sorted now. Got a mechanic friend to help. Turns out it's a dodgey wire going to fuse 13 - sometimes we have full connection, sometimes none at all, which was giving me mixed results with the tests I was doing. Still haven't tracked the part that's dodgey, but at least I know it's something behind the CE panel.

Thanks everyone for your help, it's what makes the board so damn great.

As for that mystery box, it was increase the duration on the injectors, and overfueling the car, so it runs better now with the box removed

agen7seven

I'm guessing this issues going to plague me for a while. Car starts great now, but it's performance is lack luster and backfires a bit too..

So I guess now I'm running lean.

John Speake

Either an air leak or thge MAF is badly aged. That was problably the reason for that bodged on box.

Send me your MAF for testing when you send that LH ECU back to me.....