Fuel pump running for 2sec after shut off?!

[Rota]

Hi guys hopefully someone here can give me an answer.

I have recently put a 1ggte into a hilux and my brother wired it all up for me.
Every time i shut the car off the fuel pumps keeps going for about another 2 seconds.

It doesnt sound like an issue but when uve got a bosch 044 and a carter black bolted to a steel tray in the open air they are really loud and annoying.

Is this normal for the pumps to continue after the car is shut off? Or has something been wired incorrectly maybe?

Cheers guys

[fixeruperer]

has it got an immoboilser aswell ?
definitely a wiring prob, they should turn off with the key (unless turbo timer or bad wiring)

[Rota]

Yeah its got a shitty immobiliser. No turbo timer though.

I know the relay for the fuel pump has a 2 second delay, but i think its wired wrong if its staying on for 2 sec after the car is shut off.

[fixeruperer]

, turn it to 0 .
we use them on rad fans, so when the car is off, the fan stays on for a lil but longer.

[wilbo666]

Seems 1G-E and 1G-GE are different.




My post before edit below.

That doesn't sound right...

Below is how the fuel pump circuit should be setup. You can see that as soon as you switch the ignition off you should open the "Main Relay" and disconnect power to the fuel pump!

Page 4 in the below document from www.autoshop101.com

22 EFI#3 Fuel Delivery & Injection Controls.pdf file size 727KB

Cheers
Wilbo

[Rota]

Cheers wilbo666 +rep

I'll take a look at it tomorow with that diagram.


Maybe the main relay is wired around the wrong way or something?

[Shifty]

in unrelated news can you actually buy a relay with a delay on it? i have an oil pump that i want to run for 10 seconds or so after i turn off my engine. currently just connected by a fused relay but if there is one i can get with a delay that would be ultra cool.

[Z2TT]

Hi,

I get exactly the same thing in my Soarer GZ20 with a 1g-gte. When the car is shut off the fuel pump runs for about 2 seconds. With or Without immob it does it, did it when it was bone stock no mods or no immob. Maybe it's normal?

[Rodger]

Is it possible that all factory EFI motors have this feature and is a desired thing? So when the motor shuts off the fuel pump runs that two seconds to re-pressure the system ready for the next start up.

As I observe, (I cannot hear the pump in my Camry) the motor starts within a couple of revolutions of the starter but if I let go of the key too soon and it has not fired it takes a good few seconds to fire up, as though there is no fuel until the pump has pressurised again.

Regards

Rodger

[fixeruperer]

usually there is a one way valve in the system or in the pump, so when you turn the car off, there is always pressure there.

[Rodger]

Does the ECU look at the fuel pressure and perhaps during a shut down it sees low pressure, runs the pump on after shutting off spark and the injectors, then this one way valve holds it up.

What I see at start up is the ECU not getting a running signal from the motor and then a low pressure signal and then when I refire the ECU runs the pump, gets pressure, starts the injectors and the ignition/spark. Perhaps in a normal start sequence having the fuel pressure there the ECU turns on the injectors, starts the spark and then starts the pump again when the motor fires up.

Regards

Rodger

[Rota]

Does the ECU look at the fuel pressure and perhaps during a shut down it sees low pressure, runs the pump on after shutting off spark and the injectors, then this one way valve holds it up.

What I see at start up is the ECU not getting a running signal from the motor and then a low pressure signal and then when I refire the ECU runs the pump, gets pressure, starts the injectors and the ignition/spark. Perhaps in a normal start sequence having the fuel pressure there the ECU turns on the injectors, starts the spark and then starts the pump again when the motor fires up.

Regards

Rodger

The 2 second delay comes from the circuit opening relay. I think its there so that the fuel pumps dont shut off and lean the motor out if the afm closes temporarily.

But from the looks of the diagram that wilbo supplied the "main" relay should cut all power to the fuel pumps when the ignition is turned off so that they dont keep going for another 2 seconds.

Im assuming mine just isnt wired properly.

[RA35GT]

Just thinking out loud here.

Do these engines have a stepper idle motor?

Is by any chance the fuel pump controlled (incorrectly) by the mrel output?

[rob]

the 1G-GE did this in my RA40 as well

i didnt wire it so thought at the time it was to prime the fuel pump as well

[Z2TT]

When my car is on ignition, and I momentarilly open the afm by hand fuel pump turns on straight away, when i close it it turns off straight away with no delay.

It is only when I start the car with the key, then shut the car off the fuel pump stays on for about 2 seconds, I'm pretty sure when the fuel pump shuts off there is a click in the dashboard somewhere near the glovebox.