how is this happening?

[codyc7.3]

I live in an area where diesel trucks are commonly stolen so on my 2000 sd. I installed a switch to cut the power To the fuel pump as a theft deturant. And it works. But somehow the truck still runs without the fuel pump... am I just an idiot?

 

[SPEEDDEMON31176]

That is impossible. You didn't get the right wire.

 

[codyc7.3]

That's what I said but I can hear it cut off when I flipped the switch

 

[907DAVE]

It will idle until fuel pressure drops to zero, and maybe a little more.

Are you killing the FP before you start?

 

[6.0 p-stroke]

:whs: It'll take a little while to drain the fuel in the heads, lines, ect.

 

[Whytry]

Mine has run without the fuel pump getting any power before.

 

[bad12jr]

Mine has as well ran like crap but ran.

 

[Arisley]

You have to remember that each injector is a little pump. I have heard that a truck with good injectors and no pump will actually run down the road pretty decent.

Better to cut power to the PCM.

 

[Stroker#66]

When my airdog went I drove for 50+ miles with zero fuel pressure just was a terd

 

[codyc7.3]

That's what mine is doing its just really weak

 

[Southmike]

Lot of trucks have fuel left in the head, and lines etc...iirc right a few drag racers got up to the line etc and stalled out cause they forgot to turn thier pumps on.

 

[RubberDuck]

I didn't think a Power Stroke could run without fuel pressure either. That is untill I forgot to turn the Airdog on for my pulling truck. I was just moving it around the shop, but it started ran, and even reved a few times. Once I turned the key off, I realized that I never turned the fuel pump on. Coulda knocked me over with a feather. So therefore I had to choose a different fuel shut off strategy for the puller to meet rules. Ended up killing both the Airdog, and IDM.

 

[codyc7.3]

How did you go about killing the idm?

 

[RubberDuck]

Relay on the power feed.

 

[evo45]

I was having fuel pressure issues when I first started running w85 with my fass pump. The pump wouldnt prime and would have no fuel pressure but the truck would run, it sounded like crap and wouldnt move other than at idle.

What would kill the truck is the 30 amp fuse that goes out when the fuel bowl heater burns up. Put a fused switch into that fuse and it wont start, it will just turn over. I figured that out because the fb heater went out and cooked the fuse. I dont remember what number it is tho. I am sure someone else will post which number it is.

 

[SIX_OHH]

Now this cant be good for injectors??

 

[RBernardi]

If it runs like crap turned off the bastards hopefully would get far before you caught them. Let's just hope you don't find out.

 

[littleredstroker]

wouldnt it be simpiler to kill the power to the starter selinoid? i guess to me that seems more logical.

 

[6.0 p-stroke]

wouldnt it be simpiler to kill the power to the starter selinoid? i guess to me that seems more logical.

If the truck won't crank then a smart thief will start looking for switches like that, but if it cranks and doesn't start then they are more likely to walk away from it thinking something is wrong with it. That's how I see it anyways

 

[Jason]

I had popped a trailer clearance light fuse on my truck, and I pulled a random fuse to see if my lights would work again. Well, swapped the fuse out, lights came on but my truck was running noisier than before...pulled out the manual, and found I pulled the fuel pump fuse. Truck ran for a easy 5-10 min after it was pulled out, 10* out, and snowing. I was quite shocked actually!