I just completed rebuilding the entire upper half of my Disco 1. The infamous blown gasket problem struck. PO thought it would be fine to keep driving and just add water when needed, which was never sufficient.

The vehicle ran - poorly, of course, prior to the rebuild.

I am at the point where I have turned the key. It appears I am not getting spark to the spark plugs. I have replaced nearly every single sensor there is to include brand new crankshaft position sensor, camshaft position sensor, temperature sensors, fuel rail pressure relief, fuel pump, fuel filter, fuel temperature sensor, spark plugs, spark plug wires, coil pack, idle air control.

There is fuel to the fuel rail, so that portion is running nicely. But, and as mentioned, no spark.

My first thought was the crankshaft position sensor. But, not the sensor, the wiring (pictured).

When I "play" around with the wiring, I hear a few things that make me think there is something going on with the wiring. I hear the fuel rail surge with pressure and I hear a clicking sound at the MCU. I think there may be some kind of shorting going on. But, what I 'feel' is shorting, may actually be activation because the fuel rail surges with pressure.

The wiring itself, after pulling back the outside layer, shows two bare wires. The vehicle - and, hence, this wire, functioned like this prior to the rebuild. I bought some of that spray rubber paint to cover the wires. However, when I peeled back the outside sheath, there was no covering on these wires - this is what it looked like.

How can this be? What is this wire supposed to look like?

Any help with the shorting issue would be greatly appreciated.

My thoughts are that when the clicking was occurring, the system was actually functioning properly as there was the surge in fuel. But, that was when the wires were touching. Should I spray that rubber paint onto these wires? (Note: the volt meter says the plug is pushing out 2 volts, which checks out with other postings here on the crankshaft position sensor readings. And, the camshaft position sensor is pushing out 10.5 volts).

 

I’ve never heard of a rubber paint as a wire insulator. My opinion is that the bad sections of wire need to be replaced.

 

To your question about the type of wire, my '96 uses a shielded two conductor cable back to the ECU. That is, two insulated wires inside of a shield of braided copper that is grounded at one point. The shield helps prevent EM interference due to this high frequency signal.

When I got the truck, the PO had the two wires shorted together on purpose. The truck ran, but not very well. Probably was in some kind of limp mode. I replaced the sensor and added insulation, but I think I just used tape.

 

Thanks for the input on this. I peeled back the wire to expose where the very end of where the insulation for the internal wires shows. I taped from there. Plugged it in, still no spark to the spark plugs. I have a pigtail plug coming in the mail and will arrive on Saturday. I am going to remove the entire sensor and ensure proper fit and cleanliness. I will install the new plug. That should ensure that this variable is connected. I will test for spark at that point.

I may also have another issue that I will test for: I simultaneously replaced the ignition switch. Got one from BritPart so, feel that this is a solid product. But, I have read that if the alarm is not reset properly this could cause my starter to turn, and turn, and turn, with no spark. I put the key in the front door, turned to the left, and the alarm appears to be blinking properly - one flash about every 10 - 15 seconds. Doors lock properly. I will research this next.

 

You said you have fuel pressure so it’s not likely the inertia switch, but I would try resetting it anyway.

 

Sorry, forgot I was in the D1 section. I’m not sure if you have an inertia switch.

 

When you crank it, doesn't even think about firing even a little bit? Saw no spark whatsoever in a spark tester?
Check fuse 3, satellite 1 in fuse box under steering wheel. Check for battery voltage, with key in position 2, at pin 5, white/green wire, at the coil connector.