Sudden loss of power 20V N/A

Hi, hope you can help. There is a sudden loss of power after about 15 mins driving from cold (just no drive , electrics still on so some sort of fuel starvation) and car will not start again for around 15 mins and then will only drive for about 3 mins before it cuts out again! John at MCS, who has done a lot of work on it recently, told me to start with the two relays in the passenger well which I replaced, but hasn't solved the problem.
When waiting for the car to start again, I have noticed that after I hear a faint "click", the car will restart. Cannot pin point where it is coming from though.
Car drives beautifully apart from this. Any ideas would be gratefully received.
Many thanks, Phil.

Is the injector light on when it fails to start? Have you scanned for stored error codes?

Hi. Thanks for getting back to me. Yes it is on when it conks out, but after 15 mins when it will start it goes out. When it is running it does not come on until after it dies. Then i have to wait a while, a faint click from somewhere and hey presto starts up again!!!

Have not yet scanned for error codes.

Grasping at straws here but I wonder if there is an intermittent fault with the fuel cut off switch? Or it sounds like a poor electrical connection. Maybe go through all the places touched when it was last worked on? Or immobilser fault. Sorry lots of suggestions but no concrete root cause.

My guess is crank sensor, but check for error codes to confirm.

Sounds like crank sensor to me too, the injector (fault) light doesn't come on when the engine stops running, but does come on if the fault is there when trying to start, IIRC from when my Plus did that in Holland recently, but TBH when it conks out like that a bit of panic tends to set in...

Have you checked the YCOD (yellow connector of death) under the dash?

In the 16V NA there are two of these crazy connectors. One at each side, under the dash.
Usually each one giving one volt dropping..
Removed both since they are useless, required only at mounting time.

Hi Guys. Quick update. Checked all the connectors and nothing, so then went for the crank sensor and has cured the problem. Many thanks, for all your responses and help. Phil.