Zetec crank sensor

[davidhorsfield]

Is there any history of a zetec crank sensor being effected by heat?
I'm having a trouble with the car cutting out well after the car has warmed up and gone through the warm up wizard, if I leave it to cool for a while it will then start and run for a while but always cut out again, it will never re start straight away because the switched earth that works the fuel relay and fuses is lost.
Watching the rpm in megatune, the value will for example drop from 3000 to 0 when the engine stops which makes me think I'm losing the crank signal. also when I crank no rpm is shown.
So is there any chance the heat off the exhaust is effecting the crank sensor.

ps. The ecu has been run on a test bench by efi extra for 8 hours with no problems, and i have tried a different ecu and the same thing happens. I've also re installed firmware and reverted to previous saved maps/settings.

[Matt Cramer]

Can you post a tooth log of what happens when it loses RPM? I have seen VR sensors affected by heat before.

[davidhorsfield]

I'm afraid I've never done any logging, and I don't know what a tooth log is, but If I don't have any luck with the sensor I'll look into it and try to do one for you. It's handy to know that the sensor could be affected by heat. Cheers.

[davidhorsfield]

This turns out to be a faulty plug on the crank sensor. after swapping the sensor, and generally faffing about the problem became more random and we found that if we waggled the plug we could stop the car or keep it running for much longer than before. So it's having a new plug fitted. Hopefully that will cure the problem.