With the +ve to the starter motor completely disconnected so it doesn’t operate, when you turn the key to the cranking position the voltage drops?
If so, try the same but with the starter +ve AND the feed to the solenoid removed, in case there is a fault in the latter.
Trying to get a booster pack to help turn the starter, either my second battery is not up to it or engine hard to turn.
I have disconnected the front battery cable from the starter, had to connect this cable to the brown going to the alternator as it branches off to supply fuel pump and ecu.
So, on the ecu I am seeing a 10 volt supply. With the PC connected whilst cranking (slowly due to battery), the software stayed connected to the ecu, which is saying that it is not switching off due to the earlier problem of inadequate voltage.
Still not seeing a crank speed. Running out of time or rather have run out for now.
Slow cranking could be either the battery or it could be the solenoid is making a poor contact when it actuates.
The latter is likely to drop the voltage which is why I suggested disconnecting the +ve from the starter (at the motor) then check the voltage when the key is turned to cranking.
Also to repeat this with both the starter +ve and the smaller wire disconnected from the solenoid itself.
That way you will be able to identify if the voltage drop is (a) starter motor, (b) solenoid or (c) within the wiring elsewhere.
Hope that helps!
I have listened to you. Tested. I have in fact, changed the battery, having checked the earths.
Now, I am getting 9.5 volts on cranking with all connected on the starter motor and solenoid. Fast cranking and all but, no spark still. Just rest the ecu, fast cranking still, 9.5v. Am happier with things but, no spark. New coil ordered.
Going off for two weeks however for work.
Hi Roy, that sounds better but unfortunately still not solved.
Cheers, Klaus
Plugged the PC in again to check the engine.
No error codes P000000, below this, it says ’ status of DTC: confirmed DTC
Before it stated an error. So, this seems to have cleared.
When I go on the monitoring screen, the top line says : Fuel system - Open loop ( has not yet satisfied conditions)
I can’t see any fuel line pressure sensor or transmitter so for me, pump works, pressure there.
When I crank now, turns over rapidly, software does loose connection at times, volt to ecu is about 9.4. The ecu could still be powering down.
I wish the Esprit software worked.
That sound very good 
. Although the pressure in the fuel system could still be from the initial priming. As you said you should check if the injectors are triggered by the ECU. Maybe someone else could explain what to expect on the injector connector. I never checked this on my car.
‘Open loop’ means that the injected fuel quantity is not trimmed by measuring the lambda value. This is perfectly normal as long as the car has not sufficiently warmed up. Later on the ECU will switch to ‘closed loop’ mode.
I’m afraid the Esprit software won’t help you with this problem. A standard and stable working OBD scanner would be of better use.
I’m using a hand held AutoXRay OBD scanner most of the time with independent power supply (by battery). It stays connected while cranking (well most of the time).
I bought a used one on ebay UK. There is a used one currently available on Amazon FR: http://amzn.eu/42cUKT8
But I’m sure others devices will work too, just need to check it.
What I like about a dedicated device is that I can take it out of the drawer in two or five years, plug it into the car and it will work. No driver update, incompatible OS system, missing VisualBasic DLLs or COM port trouble 
Cheers, Klaus
Okay, sounds like you have fairly normal voltages on cranking now.
Are you sure the immobiliser is working correctly? This controls cranking and coil connections separately, so the coil side can fail even if the cranking is working.
I have done away with the immobiliser. Can you explain your thoughts a bit more?
Just come back and have access to the car again.
Roy
When the immobiliser is active, it acts on both cranking and spark. The two circuits prevent (for example) theft by jump-starting, which would be possible with an immobiliser that operated only on cranking.
Hi Roy,
any updates on your issue?
You asked me before if the fan starts when disconnecting the brown sensor and I said no. But while chasing my driavbility issue I disconnected the brown sensor while the engine was running and the radiator fan kicked in immediately. So there is a fail safe mode but the engine needs to be running
If you not sure if your radiator fan is operational you may switch the fuel pump on in the Esprit V8 software to see if the communication to the car is established.
Klaus
Finally some news.
I have sent the ECU to Bluestreak in Nottingham. They have said it is knackered but, they will try and repair so, now it is in fact repaired. They tell me a couple of chip were down due to wear. Really!? ok.
So, can I be sure this is true? The truth will be when I turn the key and it starts and then try and link to the PC.
Apparently, they are the only ones in the world who want to repair them.
£315 for the repair and postage. God, I hope it works.
What do you think Klaus?
Great info. Thanks for posting
To be honest I just hope that this fixes your issue. ‘Wear’ on electronic components sounds strange but some parts like capacitors do age with time and excessive exposure to heat.
If it still does not start can you check if the needle of rev counter moves to about 200 rpm while cranking fast (preferable with the spark plugs removed)?
Keep us updated.
I sent the ECU to be checked £30 cost. They said it was dead but could repair. Was in great visual condition, no heat burns.
So, I said do it. Next day. Finished.
I did enquire further about the repair and was told it was a couple of chips. Wear but won’t happen again. I asked for a report to say what they had done.
It is a black art. Remember, I couldn’t communicate with the unit so, will fit and try a start with no plugs for rpm but have a spark plug attached to see for that spark.
If it is the fix great. If not, waste of £315 which I was just thinking get the Emerald connected which maybe I should of done to maybe see the flywheel being sensed by the computer.
It would be a shame if I have been misled because, the learning process is tainted.
Back home Next week or two.
It is possible for i/c’s to fail over time. Typically items like amplifiers can stop working or become unstable; memory eeproms can get corrupted; analogue/digital converters can fail, etc. as well as passives like capacitors too.
Knowing what to look for, and where, is the key to diagnosis and needs the right tools to test.
Hope the repair works!
Thank you very much. Great to have this info. I actually did electronics but remember very little and was only a small unit. Black art stuff now for me.
As soon as I get home, will try the car.
Here’s hoping it’s a success 
ECU back in France fitted to the car.
Battery fully charged (not new!)
Cranking, nothing. No spark nor any rpm reading showing on the STACK.
So, was the ECU indeed faulty!?
The faults they listened were as follows:
Main Relay : pass
Fuel pump relay: pass
Stepper motor reset: pass
Stepper motor idle control: pass
Lambda adjustment: Fail
Fuel cut-off: Fail
Throttle enrichment: Fail
Rev limit: Fail
Coil saturation: Fail
Ignition dwell, peak & firing angle: Fail
Advance curve with response to load: Fail
Battery voltage correction: Fail
Self diagnostics: Fail.
I changed both the probe and coil pack and battery. Nothing, no change.
Can someone confirm, to reset the ecu, door open rhd, ignition on, accelerate 4 times? Was working a few months ago but, not resetting now- no fuel pump sound… Update: pressed the alarm on and off, the ignition on again. Yes, the above works.
Second point. I am now cranking and I hear the fuel pump priming again- whilst cranking. Is this correct. Would make sense but, couldn’t remember that?
So, I guess wire up the Emerald.
Will try and upload their report (Blue Streak) ECU repair shop in Notts.
Very sorry to hear that.
No revs shown while cranking (if long and fast enough) is still strange. This may still indicate a problem in the cranking sensor circuit (wrong flywheel pattern, wiring, etc.).
I can’t remember if the fuel pump primes while cranking on my car. This could be caused by a voltage drop while starting to crank.
I will check it the next time.
Keep trying and keep us updated. I’m sure you will finally get the car running.
Klaus