Crank Sensor / ECU / Cam Sensors - Help!
 

As a non-mechanical owner of a 2004 S2000 I find myself a little out of my depth but would really appreciate some advice. This all started about 4 weeks ago.
1. Started the car as normal and drove for approx 30 minutes. Parked the car and switched off the engine for 20 minutes. When I restarted the engine it only took on the 3rd or 4th try. This had not happened before.
2. Later that day I started, drove and stopped the car as normal. At the end of the day the car started first time but the car cut out while driving after about 20min. Noticed a clicking sound from the fuse box area below the steering wheel as the car was cutting out. Tried restarting a few times. Each time the motor turns and then cuts out. Towed to the mechanic who has serviced this car and other previous cars of mine
3. I was advised by the mechanic that the problem is electrical and so the car was taken to an auto electrician
4. The auto electrician tested the car and found that the crank sensor was faulty. Crank sensor was replaced but did not resolve the problem.
5. Auto electrician advised that the faulty crank sensor may have caused a problem with the ECU. ECU has been tested by independent ECU repairer and no fault found. The car has been re-assembled and taken to a Honda dealership for diagnostic testing and no fault has been found. Honda dealership has advised that the cam sensors may need to be replaced but this may not solve the problem.
Before I go any further down this path I'd like to know if anyone on this forum can advise?
I'm happy to do some further testing if neccessary.
The car is at 95 000km / 59 000miles
I've owned it since July 2016 and put approximately 6 000km / 3700mile on it. Two minor services have been done in this time. Not sure of service history as I have annoyingly lost the service book.
If I've missed a post about this same problem please direct me to it.

Regards,
Grahame
Johannesburg
South Africa

That clicking sound from under the steering wheel area makes me think there is a problem with the main relay.
This big relay controls the fuel pump among a few other things.
When you turn on the ignition the fuel pump should run for a couple of seconds, try listen and see if it does.
It could be hard to notice so maybe have someone else listen inside the trunk.

I'm ignoring what your mechanics seems to have found since it's most probably not true :)

Thanks. Will see if the fuel pump is running

Think as said it will only prime
put hand on under dash relay and feel for 3 clicks<when ignition is switched too on>

Really hard to follow your post.

Does it turn over easily on start up?
Does it crank but not start on start up?
Does it turn over, crank, start, and then die?

What has been done to the car recently? Valve cover gasket replacement? Compression test? Overheated? Stored away for months?