kill switch off + 0 psi = still runnin?

[JasonCzerak]

I installed my kill switch some where within the lift pump wiring. The DC intank pump setup helps with this since there are extra wires you can tap into.



Anywho, When I first got this setup, I forgot to flip the switch a few times. and like a charm, she stalled out after a minute or 2 of idle. And one time, 2 blocks of travel. The travel thing is nice cuz if you rip my truck off in a parking lot, you'll get in the street and stall out.



Any who. this morning I forgot, first time in a month or so I"m sure. And I let the truck idle for about 10 minutes got in and the low pressure fuel gauge was at 0psi!!!! and she was still running!!!



flipped the switch on and drove off at the typcaly 11psi. I musta got the LP just in the right spot when I shut things down lastnight I suppose eh?



I figure the stalling would be ok and do very little if any ware on the CP3, but what about idling at 0psi for a while?

 

[pwr2tow]

I doubt it hurt anything idleing. Duramax runs without a lift pump. There is more restriction when your pump is not running but I doubt it hurt anything.

I'ed bet if you would have taken off with the lift pump switch not on the truck would have died, but still not hurt anything.

Nice setup with the kill switch.

 

[MCummings]

I figure the stalling would be ok and do very little if any ware on the CP3, but what about idling at 0psi for a while?

Cummins okays these pumps to operate at 0PSI. Just not under vacuum. This is not a longevity issue, but a performance and emissions issue.



Merrick

 

[robertyoke]

I tried a kill switch hooked to my fuel pump. Had it off one day that my truck sat outside the garage, forgot to turn it on and drove half way to denver 30 or so miles before I noticed the fp gauge was on 0. Truck ran fine did not notice anything wrong while I was driving. It was cold and I was being easy on it but no damage to cp3. But also not the gratest kill switch IMO.

-robert

 

[Jeff_K]

Is this for theft prevention? If so, then why not tap into the clutch switch wires? The clutch switch must be made to start the truck, so just add another switch in series.

 

[JasonCzerak]

Is this for theft prevention? If so, then why not tap into the clutch switch wires? The clutch switch must be made to start the truck, so just add another switch in series.

Think like a thief. I'd look for clutch wires that were cut into first in a manual. in my case, the wiring looks stock with the exception of some wires going to some gauges, under the dash. and those go instantly off to the side from the firewall (for the a pillar, and over head console pods). There are a lot of the same colored wires in that harness to choose from to get the truck's LP to run Debugging problems later will be worth the security this provides.



It's just weird. up until now, I figured a dead/broken/off liftpump would put enough restriction on things to stall the truck out once the filter canister emptied out. And has until now. And looks like I'm not the only one with a truck that will run with a lp that doesn't run.



And my theory is, if the truck get's stolen and moves then dies in a very inconvenient place. the thief will leave and run.

 

[Jeff_K]

Interupt the neutral/park sense wire at the ECM then. Pin 9 on the 50 way connector.

 

[MAshley]

I think you should just get the Trunk monkey installed