I'm currently building a new wiring loom for LFB and will be re-using the shielded HF sensor cable. However, the damn thing is a good five feet long - does it need to be this length for timing and signal propagation purposes or can I give it a good pruning?

In the absence of any other information, I pruned it. Severely.

as long as the shielding is still in place ....shouldn't be an issue dai

Thanks Charlie. The length of it made me wonder if the ignition circuit allowed for the amount of time it took for the signal to propagate from the sensor to the igniter.

As it is, I checked a second (discarded) loom and came to the conclusion that it was more likely that length for production purposes. It goes down the right side of the loom, along the crosstube in front of the relay box and then back up the left side of the loom to the ICU. The long way round.... very long way round.

Doesn't sound standard to me. I've recently been researching HESensors and I've seen that sensors for industrial applications can have varying lengths of shielded cable up to 10m so that signals can be routed to monitoring equipment. I don't think the length will affect the signal at all.

These things don't work at high enough frequencies for conductor length to be a consideration. it needs to be in the giga hertz range before conductor length becomes at all important

Thanks guys - the info is definately appreciated.