AE82 4AGE bigport fuel pump relay signal?

[matt99]

Evening all.

Just putting an AE82 4AGE bigport into a KE70, something I USED to do all the time. Now I just dump dirty datsun motors in them. Anyway, I can't get the fuel pump to prime. Myself and a friend both agree that we thought that the "circuit open relay" had a negative output that you took the ground for your fuel pump relay to.

However I can't get a negative OR a positive signal from this pinout. WHY? Or WHICH ONE did I used to take it/meant to take it to?

My 4AG 86 has the same issue that I would like to rectify also.

Thanks, Matt.

[Javal]

Yo.

I just wired one up a few weeks ago. It doesn't 'prime' the pump. I thought it might, but it doesn't. From the sound of it you don't have the pump working at all.

Using a Toyota COR?

'FC' on COR needs a -ve trig from 'FC' terminal on ECU
STA needs a +ve trig from 'STA' starter wiring
'FP' (can be 'FS') to fuel pump, positive output
E1 to Ground
B+ to EFI power

[Hen may possibly be a nut]

I'm a little hazy on this, but I'm not sure factory Toyota ECUs prime the pump when you turn the key to ignition. Usually the COR is run by STA when starting (which gives +12V to a COR input), and either the ECU FP pin, or the AFM contact when running (both of which ground another COR input).

Also the COR is wired (from factory) to give +12V to your fuel pump. So it sits between your pump and the battery. The other side of the fuel pump is grounded.

Some diagrams

[matt99]

Thanks for the fronts guys, I have been trying to use a standard relay to do it instead of a COR or two standard ones. I think to keep it simple I'll just swap them both to COR.

I'm too used to SR's now, when the ECU receives power it's fuel pump circuit puts out a negative signal for a couple of seconds then drops out. Hence, I use that as the ground for the pump relay trigger and bobs your uncle.

However I'm sure my old 4AGEs all used to prime prior to starting, I don't think the COR relay will overcome this from what you guys are saying? Is that correct?

[Matt]

Some of the bigport ecu's do prime the fuel pump when you turn the ignition on. Nothing special in the wiring, all you do is wire it as above and the ecu does the rest

[matt99]

Yeah I know it's within the ECU that the circuit opening happens, I just couldn't work out why it wasn't getting an output on the circuit opening relay pinout.

[Matt]

Blown transistor on the ecu , happens if you feed 12v into the fp pin

[matt99]

Damn thing won't run now anyway. Got injector pulse, got spark, got compression, got timing, got fuel. Piece o' shit.