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Fuel pump electrics.


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over the last few days ive been busy fitting injection to my sports hatch, ive now reached the point where im checking the electrics work.

So far everythings working bar the fuel pump.

Im not getting a live feed to it from the relay.

Does anyone know what live feeds should be on at the relay to switch it?

Fingers crossed its a wire ive missed somewhere.

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Try googling 7-pin tachometric relay.......... it's friday and I've had a few so the heid's no workin' too good............................................................................





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Picture speaks a thousand words so here goes, remember that I'm looking at the plug from opposite ends but once you're orientated it will help.

Car loom plug


Injection harness plug


Basically if you have an injection loom try get the plug from the injection loom for factory look if possible, then all you have to do is wire that in and they magically only fit one way round.

Not done this since a few years before '99 so bear with me.

IF I remember rightly the Black with Red trace sw-rt on the diagrams, the green and the black will all be in the loom over the heater for you to cut into.

As for the black ignition live, connect it to the one to the coil NOT a separate one, for the fuel pump run a separate new wire and fuse as apprpriate.

When fitting a jetronic 3.0 to check it was good me and a mate ran it up sitting on a stump at the side of his GTE. We connected the injection loom to his car, connected his fuel system with long pipes. We used the ignition pack bolted to his engine and connected a separate live to the coil pack for convenience (length of wires) we got spark but didn't run. I realised I couldn't hear the injectors. We then connected the coil pack to the car wiring and it ran. I think the injection picks up a pulse, don't know if from black or green. Maybe the black doesn't make a diff, never had cause to examine it further, would make sense to be just the coil for trigger so maybe its just a be aware point if you have problems.

In a GTE loom although if you strip the wires back in the car loom it looks like they are separate black wires they are joined inside the loom a couple of inches interior side of the car loom grommit. Make sense?

Confused? lol

Oh yeah, no warranty implied or given, if your car melts unlucky.

Basically if everything looks right and the injection relay is the only problem you have, cars will usually run with a faulty injection relay as long as it is plugged in as long as you furnish power to the pump by some other means.

So after checking out the blue for a live while cranking or running as above go from there.

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Off the top of my head I think the relay connections go something like this:

30 - permanent live, thick red cable.

87 - feed to fuel pump, thick white or blue

87b - feed to injectors, throttle switch etc, thick white or blue

15 - switch live from ignition switch for relay coil - thin black

1 - signal from ignition hall sensors, thin green

50 - switch live from ignition for relay and thermo time switch, cold start valve etc, thin red black

31 - earth for relay coil, thin brown.

Wire colours may vary on different cars .Also I might have the feeds the wrong way around. Some other manta nutter will probably correct me.

In an emergency or for testing purposes. If you suspect the relay then bridge terminals 30, 87 and 87b together. The pump should run (all the time!!!!) and you should have power to the injectors. The car should also start. You can drive like this but I wouldn't recommend it for too long.


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Would you like to run through the wiring you have done to install the fuel injected engine?

Did your car have a rev counter to start with or not?

You should have used:

Black from ignition switch to coil

Red & Black from ignition switch to starter motor solinoid.

Green attaches to connection from the coil to rev counter.

A feed, standard colour is blue, to the fuel pump.

A thick red that attaches to the starter.

An earth wire that attaches to the inlet manifold.

That is it.

If the relay doesn't get a feed back from the rev counter, and red & black cable it will turn over and start but die straight away.

If your wiring is ok the try what i mentioned about connecting the three connectors together. If it starts and runs now it is your relay.

30 - permanent live, thick red cable.

87 - feed to fuel pump, thick white or blue

87b - feed to injectors, throttle switch etc, thick white or blue

Did you have the engine running before the conversion in the donner car?

Is your static timing right?

Do you have the correct ECU?

Did you damage the fuel injection harness during installation?

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At the relay i have

Red perm live

black switched live

red black switched on cranking

green revcounter its getting a signal

Brown earth to manifold

turn ingition on to cranking relay clicks but no power goes to 87 or 87b.

Ive bridged thes 2 conections and the car still only starts and runs for a few seconds pumps.

Im curently thinking duff relay and or ecu. Will try another set this afternoon.

The engine was runining before the conversion but with a misfire. Checked the static timing usint the mark on the flywheel instead of the pulley found it to be a tooth out. Ive reset it to the marks checked re checked and checked again.

Cheers for all the help guys i will get this thing running even if i have to throw spanners at it.


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Is the black connected to the ignition live connected directly to the black wire that feeds the coil pack?

And have you taken account of the fact that if your car had points that black only has power when cranking and the rest of the time it is powered by the resistance wire, usually translucent yellow?

Only applies if you didn't originally have electronic ignition on a 12V feed of course

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Earth loop bolted to plenum?

Ring terminal to feed EFI loom under the right terminal nut on the starter?

The AFM on some jectronic seems to have a switch in to cut the pump if the flap doesn't move.

Usually turning the ignition lights on pulses pump two seconds then stops so sounds mostly right.

Fuel pressure feed to T on fuel rail and return from pressure regulator to tank?

ECU earthed?

Senders on therm housing right way around?

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