Killing a Diesel - a detailed how-to (much info on commonrail technology)

[torino73]

Originally Posted by Piwoslaw

How about:

1. Kill the lower pressure fuel pump and see what happens
2. Hack the fuel pressure sensor to tell the ECU the pressure is too low/high
3. Trick the ECU into thinking the engine speed is such that the fuel should be cut to the injectors
4. Cut sygnal to one of the injectors and see if the ECU sends an emergency shut down (rebuild engine if not)

Any safer ideas? As I mentioned earlier, the engine doesn't react to unplugging neither the cam, nor the crankshaft (engine speed) sensors, though I didn't pull both at the same time, so maybe the ECU is able to get its info from only the one that is available? Or maybe instead of unplugging it, the sygnal lead should be grounded to mass? I'd like input from anyone who's tried, even those dumb hall sensors cost a fortune.

Do not kill your lift pump. Starving your injection pump, especially such a high pressure pump, will cause cavitation. I work in an industry that uses high pressure pumps and I’ve seen the damage of cavitation. It essentially pulls the metal right off the inside of the pump.

Older diesels used a valve to cut air in and emergency. No diesel will run without air. Have you considered an actuated swing-out, or butterfly valve before turbo?

I’m a newbie, so I’m a little naive. What’s the purpose of cutting the engine like you are trying to do; to keep rolling at speed with the engine killed? Why not just turn the ignition off? It works for me.

[dcb]

Originally Posted by torino73

...What’s the purpose of cutting the engine like you are trying to do; to keep rolling at speed with the engine killed? Why not just turn the ignition off?

If you can do something like have a microswitch on your shifter to kill the engine, then it is fluidly becomes part of your driving and does not kill the speedo and everything else (or risk locking the steering column, though not a huge risk). Also some of us have very old ignition switches that don't need the aggravation.

[JasonG]

Originally Posted by torino73

Do not kill your lift pump. Starving your injection pump, especially such a high pressure pump, will cause cavitation. I work in an industry that uses high pressure pumps and I’ve seen the damage of cavitation. It essentially pulls the metal right off the inside of the pump.

Older diesels used a valve to cut air in and emergency. No diesel will run without air. Have you considered an actuated swing-out, or butterfly valve before turbo?

I’m a newbie, so I’m a little naive. What’s the purpose of cutting the engine like you are trying to do; to keep rolling at speed with the engine killed? Why not just turn the ignition off? It works for me.

Don't kill the lift pump !
Having a lift pump go out tends to wipe out the main pump. That's $2000 last time I checked.
I would cut power to all 4 injectors. Its safer than the other options.

[torino73]

Originally Posted by dcb

If you can do something like have a microswitch on your shifter to kill the engine, then it is fluidly becomes part of your driving and does not kill the speedo and everything else (or risk locking the steering column, though not a huge risk). Also some of us have very old ignition switches that don't need the aggravation.

Gotchya!

What about a high pressure 3-way valve in-line with the common rail? Your switch would send supply fuel to return AND kill the injectors. That way you don't create a high temp condition from the IP running and damage to the injectors from dry-firing.