Your friend the circuit opening relay (or how to wire fuel pumps)

[dumbass]

how bloody hard can it be

hold relay away from u and look into terminals

top row is 3 pin

middle pin is power from efi relay black/red wire
top left is start signal so 12vs only when cranking black wire
top right goes to fuel pump positive blue/black wire
bottom left is earth i think white /black wire
bottom right is green/red wire negative trigger from ecu or air flow meter

some 6 pin relays have a centre pin at bottom this is black/orange and goes to ign

i dream about these relays in my sleep

and when i wire up an ecu with a fuel pump controller i piss them off
and use my custom tacho relays to trigger the COR as most tacho relays are pos triggered

[Omegaman]

Guys, using yr diagram to compare to my 18rgeu diagram. It seems there is a slight difference.
As my engine has the AFM. can one of you guys confirm which is the right way to wire the fuel pump.
Using my diagram and any changes, can someone help (draw me, or advise) how it should be wired.
I've been having issues with the fuel pump not comming on when the ignition in start. i get Ohms from the AFM but no volts from the relay wire from the relay point.



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[RA35GT]

make sure E1 on afm is earthed.

Open flap and make sure E1 and FC short together, i.e. FC should be earthed with the flap open.

your diagram above doesnt show the starter aux relay which runs the fuel pump when the starter engages (by earthing the same wire as fc is on)

Use the second diagram in the original post.

The afm is not smart in any way, it is just a bunch of contacts wiping across tracks.

Fuel pump control is a secondary function and is independent of the air flow measuring.

[Omegaman]

thanks RA35GT, once the rain stops, i'll check it out. cheers

[Golberg]

Can I make a potential suggestion to be altered on the initial post?

I think needs to be noted that not all AFM engines switch the fuel pump through the AFM.

Many newer Toyota's have an AFM but the ECU output's an FC signal to turn on the COR.

[dnegative]

Just be lazy and use a lpg safety switch lol

[Omegaman]

Guys, using yr diagram to compare to my 18rgeu diagram. It seems there is a slight difference.
As my engine has the AFM. can one of you guys confirm which is the right way to wire the fuel pump.
Using my diagram and any changes, can someone help (draw me, or advise) how it should be wired.
I've been having issues with the fuel pump not comming on when the ignition in start. i get Ohms from the AFM but no volts from the relay wire from the relay point.



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i have attached my relays in the hope someone can make sense of my wiring and why my pump does not trigger.
the relays are fused. looking at my wiring diagram and the back of the relays, where is it wrong.
i admit the red/black wire is the unknown, im asuming its connected to the EcU (+B)

ra35gt, the afm wires are earthed correctly from what i can see.
Any help, would be great, i've struggled with this for a while now.

http://img339.imageshack.us/slidesho...id=afmplug.jpg

[RA35GT]

Hey dood,

Have you physically tested it for connection to earth or just visually? (multimeter on continuity check to be absolutely sure.)

Then disconnect afm. earth the fc wire. pump should run, if not, wiring has issues.

Check relays work. put 12v + ground on the relay coil terminals. make sure it clicks and the other two terminals are connected.

make sure the afm wiring connector connects to the fuel pump relay. (continuity using meter)

ensure ignition 12v and battery 12v is at relay connector at appropriate times. (with multimeter)

(Also, from factory the jumper wire on the afm connector shouldnt be there and the white wire is earthed and the white green would go to the relays. shouldn't stop it working however)

Also, those wires look really sh1t, I have heaps of leftover terminals for the AFM if you want to crimp some new terminals onto new wires.

Those relays look to be connected properly. the wire you labelled not sure would be the EFI Main output (goes to +B on computer)

[Omegaman]

Ra35gt.
yes I did check with multimeter. Not just by sight. Sorry.
I'll go through yr steps later in the week. Had no time this arvo.
The B+ is what shows on the wiring diagram....??????
I'll give a few places a visit the find new plugs, they do look dodge.
I really appreciate the advice. Wish me luck
I need to take a step back and start the checks again.
Cheers

[RA35GT]

Sweeeet. Just checking.

Yeah man, +B as per the diagram you posted.

Plugs/connector housings should be fine man. Just the wires themselves look a little past it.
New terminals (that crimp onto wires and you push into the housing) I can help you with so you can crimp new wires into them.

Good luck man, wiring is pretty easy. Just gotta work through it methodically. One wire at a time, knowing where each end of the wire is going and testing them in all conditions to make sure it operates as expected.

[BradW]

The first thing I would do is get rid of the scotchloks and twist and solder the wires together. The only thing scotchloks are good for is causing bad connections. In case you don't know what they are, they are the red and blue connectors you have on the ign and afm wires.
I'm not saying these are your problem but they definitely aren't going to help.

[Omegaman]

The first thing I would do is get rid of the scotchloks and twist and solder the wires together. The only thing scotchloks are good for is causing bad connections. In case you don't know what they are, they are the red and blue connectors you have on the ign and afm wires.
I'm not saying these are your problem but they definitely aren't going to help.

Yes, fair enough on that. i will get rid of them.
they were there to attach a relay for the lift pump.
To see if it worked, as you can see it didn't..lol

[BradW]

Have you tried moving the afm flap with your hand with the ignition turned on (don't worry about trying to start the engine) and seeing if the fuel pump runs. The fc contacts in the afm don't close until the flap starts to move.

[Omegaman]

Have you tried moving the afm flap with your hand with the ignition turned on (don't worry about trying to start the engine) and seeing if the fuel pump runs. The fc contacts in the afm don't close until the flap starts to move.

Hi, yes I have tried that also.
The Afm was also tested with the multimetre.
also I have a spare Afm which got the same result.
This is starting to bug me big time.
Once I do these test again, this weekend. If nothing is fixed I will pull out the harness and double check it.
Luckily it's easy to disconnect.
I remember 2 yrs ago an electrician had a go at bypassing something to do with the relays. Maybe he changed something I don't know about. It went to him on a trailer and back, so who knows.

[BradW]

Does the fuel pump relay click when you move the afm flap with the ignition on?
Also put a jumper wire from the orange battery wire to the black fuel pump wire, and see if the pump runs.