Thread: F1 Fuse Pump Fuse

Originally Posted by BradC

Ahh, that's dead easy. There are 2 valves on the HPFP, the volume control valve and the pressure control valve. Disconnect either of those and they open right up. In the case of the PCV it drops the fuel pressure below that required to support injection and he engine will die. In the case of the VCV it diverts all fuel back to the return line. Either will stop the engine.

Edit. The VCV *closes* on no power. Same result.

Two questions if you can please:

1) if I pulse one of these valves on (couple seconds)/off (Couple seconds) for a minute will the engine splutter but not die on the first pulse or will it just die and require a restart button.
2) bit worried that the little ****s are doing 140kmh down the highway and I cut it - they will loose power steering (don’t mind if they kill themselves but it’s the other people I worry about). Is there a way to get the engine to just go to idle?

cheers

Originally Posted by HarryO

Two questions if you can please:

1) if I pulse one of these valves on (couple seconds)/off (Couple seconds) for a minute will the engine splutter but not die on the first pulse or will it just die and require a restart button.
2) bit worried that the little ****s are doing 140kmh down the highway and I cut it - they will loose power steering (don’t mind if they kill themselves but it’s the other people I worry about). Is there a way to get the engine to just go to idle?

cheers

1) It'll kill the engine and set a fault. If you pulsed it short enough the engine might well stay running but it'll go into limp home mode. You could play with the timing but you're at the mercy of the ECU.

What happens if you are doing 140 and kill the engine manually? I'd have thought the engine would continue to turn back through the transmission and torque converter, but I don't know what these magic slushboxes do. My experience with slack-o-matics stops with a late 80's 3+OD Aisin transmission.

2) That's above my pay grade. I'm sure you could get the ECU programmed to do something like that. You'd probably be better off breaking the connection to the accelerator pedal sensors if that's your aim.

Like the idea of the accelerator position sensor - it’s just 2 potentiometers in parallel with 5v circuits.

Might just combine it with the volume valve you spoke of so that for 1 minute it will idle (acc sensor) and the just die (volume valve).

That should be safe enough..

Cheers..

Make sure you let us know in detail how it works out. Include logged faults and performance observation. You might be onto something worth investigating if it's reliable and reproducible.

Just remember that the fuel also acts as a cooling and lubricating fluid for the hpfp. Starving this pump could cause you more issues than you are trying to solve.

A simple electronic immobiliser that disconnects all power to the ecu may be a simpler approach?

Originally Posted by Eric SDV6SE

Just remember that the fuel also acts as a cooling and lubricating fluid for the hpfp. Starving this pump could cause you more issues than you are trying to solve.

A simple electronic immobiliser that disconnects all power to the ecu may be a simpler approach?

Well I’d have said the second between it being starved and the engine stopping is negligible. Remember the pump has to run without fuel the first time it is run anyhow. It’s also not like the immobiliser will be triggered regularly. If ever would be surprising.

If you interrupt the MAP sensor circuit then the engine will go into restricted performance mode but will still run on a maximum of very light throttle, so no loss of power steering or brakes and is still driveable - just. The engine will appear to have developed a fault.

I wouldn't interrupt the HPFP in any way.

Originally Posted by Graeme

If you interrupt the MAP sensor circuit then the engine will go into restricted performance mode but will still run on a maximum of very light throttle, so no loss of power steering or brakes and is still driveable - just. The engine will appear to have developed a fault.

I wouldn't interrupt the HPFP in any way.

I like this - would make them think they have stolen something unreliable and stick with knocking off Toyota’s.