@db4690 writes …
Can somebody tell me where OP said he had a hall-effect crankshaft position sensor?
OP didn’t say that, but @“Honda Blackbird” writes
I believe it is nothing more than a "Hall Effect" sensor, but I could be wrong bout its design.
They started replacing the sensor today. Apparently it´s located in a tough spot so they won´t be able to finish today.
They also said a pretty alarming thing.
If the ECU is broken and needs to be replaced, I would have to buy a new ECU. Apparently it is not possible to buy a used one. Because they need to be programmed to the specific car. And this information comes from the people at Peugeot.
But that makes me wonder. Why wouldn´t you be able to reprogram a used ECU?
Hopefully it’s the crank sensor. Let us know.
Crank sensor replaced and it still does NOT START.
Buying a new ECU would cost as much as the car did. So that is not a choice.
What to do?
No . . . an engine control module needs to be “married” to the vehicle
A used engine control module is a paperweight for anything other than the vehicle it was “married” to
I think your auto shop teacher friend needs to perform some more diagnosis
While it certainly is possible that the control module is faulty, it’s usually the last thing to go bad
You need to start at the top . . .
Good battery and connections
Engine is not seized . . . bar it over with a socket and a 1/2’ breaker bar to make sure
Spark . . . bright blue using a spark tester. Pathetic orange spark is not good enough
compression
valve timing
fuel pressure
For fuel pressure and compression you need numbers, not just guesses
For example, pushing on the fuel pressure test port schrader valve with the ignition on and some fuel squirts out doesn’t tell you very much
And for compression, we need numbers. Simply telling us “Such and such said it’s fine” isn’t really saying much
Make sure your crank sensor’s power, reference and ground is good
Does it run briefly with starting fluid?
Are you 100% certain you have more than enough fuel for the engine to start?
I doubt the problem is the ECM. If it is ECM related, more likely to be an ECM connector is a little corroded. But if the ECM is determined to be kaput, try Googling “Peugeot Module Rebuilding” or something to that effect. There are companies – at least here in America – that take a defective ECM or ABS modules, fix it, and mail it back to you. It usually takes 1-2 weeks. Since it is the identical module that came w/your car, just fixed, there’s no reprogramming issue.
There’s probably companies in your area of the EU that do that too for Peugeot branded modules . One of those companies that does this in the USA is called “Module Master”. These auto module rebuilding companies deal with this problem day in and day out so know a lot of tricks. They can sometimes advise the car owner on how to fix the problem themselves, or at least determine if it is fixable or not.
It does not start at all with starting fluid.
And yes it has fuel, not alot but there is fuel.
Yep, we were talking about trying to find a company that could fix the ECM.
Thinking of going with this company:
Tomorrow we are going to tear apart the relaybox to see if there are broken relays.
One idea, since you plan to remove the ECM anyway, do that. (By the way, I’m still doubtful this problem is the ECM.) But since you are doing it anyway, remove it then put it on your desk with good lighting and do a careful look over, both sides, using a magnifying glass. Look especially for traces on the circuit board for cracks in them. And for soldered connections that may have cracked and become de-soldered. If you find any broken connection, fix it by re-soldering. And look for any component that looks like it has overheated. Use your nose too, any unusual smell could be a burned component. Then use a pencil eraser and clean the traces of all the pcb-edge connectors you have. Then do the best you can to clean the connectors and reinstall the ECM, that might be enough to fix it.
Now the car has been sent to Peugeot for analysis.
This problem does sound like you could use some expert help. Good idea you have to ask Peugeot tech experts for some guidance before going on what might prove to be a never-ending parts replacing spree.
Finally the car ended up at Peugeot. They analyzed and found.
Drum roll…
Broken Fuse Box.
Replaced it with a new one. Pretty costly, but now the car runs fine.
More proof that with modern cars a proper diagnosis is usually the lower cost option to the owner than throwing parts at the problem. Thanks for letting us here on Car Talk Forums know the result, and happy motoring.
btw … Didn’t Columbo drive a Peugeot? I wonder if he ever had this fuse problem … 
The fuse box on my 70’s VW Rabbit got damaged by overcurrent on the bus bars through the fuel pump circuitry. It heated the bus bars enough they expanded and cracked and even melted somewhat the plastic part of the fuse box. The replacement part wasn’t overly expensive as I recall though. Maybe $125 at the time.
OP, this reminds me. If this could be an overcurrent problem elated to the fuel pump, be sure that the fuel filter isn’t clogged, as that can cause the fuel pump to strain and produce an overcurrent condition. It is possible for a tech to measure the current to the fuel pump and compare it to spec.