Fuel cut off for Ford Contour

[Rainh2o]

I was playing with the idea of putting in a switch on the cam shaft sensor wire to cut the engine off for coasting. Before I hacked the wires for this sensor I decided to start it and then pull the sensor wire off and make sure it dies smoothly. I pulled the wire off, and magically the car continued to run.

Why?

Is it also using the crank shaft position sensor as well? That doesn't make sense because when I popped my timing belt on the highway, the car instantly died so I assumed this would kill my engine but it don't.

I can't use the ignition relay because when I pull the relay, although the engine dies fast, when I plug it back in the wipers make 2 passes, strange little quirk or indication I suppose.

When I use the fuel pump relay it doesn't die smoothly and takes a bit to start back up, which I find disturbing if I had to start it back up quickly on the highway, besides I don't like the rough way it dies.

Now what should I try? Ignition coil power?

[moorecomp]

Injector cut. When I did mine on my 2.0L ZETEC, I also tried the cam sensor and the crank sensor, and neither one would kill the engine. I did an ignition cut for a while, but the unburnt fuel hitting the cat caused a SES light. I then did a normally closed momentary switch in the common feed wire to the injectors and it has worked great for more than a year. Got to get pics of my "stealth" kill switch up someday. Put the switch in the center console so the release pawl on the bottom of the e-brake lever contacts the microswitch. To kill the engine, I just push the button on the end of the e-brake. And no, it will only work when the brake lever is all the way down, the engine does not die when releasing the brake if it is engaged.

[Rainh2o]

Looking at my schematic in the manual it looks like each injector has its own route/wire to ground. Bummer, means 4 wires. I'll have to check into putting a relay for all 4. I like the idea for the stealth switch location and operating though!

[moorecomp]

Put the switch in the positive feed wire that is common to all 4 injectors. Look in the wiring diagram, and you will find it. Some have used relays, I did not because the injectors in my car are 14.4 ohms each, and with only one firing at a time, you are looking at only 1 amp through the switch. Heck, interior dome lights are more that that. Like I said, I have not had any problems with mine and have been using it for over a year and I EOC a lot. I did put spade disconnects in the wires under the dash, so if I do have a problem, it would take me about 30 seconds to bypass the switch.

[Rainh2o]

my diagram shows one wire for each injector coming from the ECU and then one wire from each injector going to a ground point. Looks like they are all separated, nothing really in common other then the ground point. I think I will have to locate the ground point and put something in at that point.

After reading through the service manual a bit more though it sounds like it is using the crankshaft position sensor but it still doesn't explain why it died when my timing belt only snapped, unless there is a difference between idle and higher RPM...may have to find the crank position sensor and try that first, otherwise it still looks like 4 separate wires.

[moorecomp]

The wiring diagram should show the wires coming from each injector and going to the ECU are each a different color (tan, brn/blu, brn/yel, and white or something like this). These are how the injector gets it's ground, inside the ECU. The other wires from each injector are all red in color and go to a common point. This is not a ground, but a junction point for hot wires. Unwrap the fuel injection harness far enough to find each of the red wires and follow to the junction. Cut them, strip and connect the 4 together plus 1 wire running to your switch. Then connect the other wire to your switch to the junction point the red wires used to be connected to.