306 GTI 6 Wont Start

[306GTI]

Hi from New Zealand As the title suggests the 306 that I am working on is not starting.

I would really like to get this car going so that I can take it for a test day at Pukekohe before the end of the month.



A bit of background...
The car was purchased t be raced in the 2K Cup and only made it to a few testing/playdays. As a result, the car sat in storage for about a year and now it won't start.
The car has been to two auto sparkies who are of the opinion that the ECU is at fault. The ECU is a Magneti Marelli IAW 1AP.10



I don't know how to test the ECU myself and I'm hoping that some of you could shed light on the topic. How can I confirm if the above diagnosis is correct? What are the symptoms?



From the testing that I've done, I can confirm the following things:

1. The fuel pump is priming (on the key turn) and pumping fuel into the fuel rail.
2. All of the injectors work and the solenoids 'click' when 12V is applied.
3. The coils are all operational and are all capable of creating an arc between the ground and center electrodes (the plug gap) of the spark plugs.
4. There is air.

Here is a photo of the engine bay.




I can confirm that all of these pieces are operational as a result of bench testing however, I cannot confirm that they are working once installed. In other words, I have not checked for a pulse from the ECU to the coils/injectors.

My next steps are to check for fault codes and the check for a pulse to the injectors and the coils.

Is there anything else that I should be looking into?

Any and all help is appreciated.

Cheers,
Justin.

[Oldpug]

I bet its NOT the ECU,probably something stupid,like "green" wires,bad earth etc.. As its been standing for a year or so I suspect the battery has been disconnected/replaced/charged so could be something to do with the immobilizer? Has this car got a square push button on the steering column cowling? if so press,hold and switch on the ignition, 4 ways should flash for a few seconds.

[306GTI]

I bet its NOT the ECU,probably something stupid,like "green" wires,bad earth etc.. As its been standing for a year or so I suspect the battery has been disconnected/replaced/charged so could be something to do with the immobilizer? Has this car got a square push button on the steering column cowling? if so press,hold and switch on the ignition, 4 ways should flash for a few seconds.

I'm thinking the same thing at this stage.

The battery has definitely been replaced at some stage. Though I don't understand how that would affect the car. What is the impact of switching the battery for a new one?

Unfortunately, after taking the plastic covers off (from around the steering column), I cannot see a square button.

[306GTI]

Update:

I still haven't got the car started... Also, the windows have stopped working... My best guess right now is that it's the immobiliser that's stopping the car from running. I literally know nothing about the security systems on these cars so, I've started to take the interior apart to get a better look...


Here are some photos of around the ignition and the key:




I'm not sure what the black box (that's on the ignition barrel) is. After opening it to have a look inside it looks as if there are some copper winding. So perhaps this is an aerial?






Looks to be a transponder inside the key. Unfortunately, this is the only key that I have.




Does anyone know what the missing relays in this image do? Where can I find a fuse box diagram for both the internal fuses and engine bay fuses?

[Hell Razor5543]

The loops around the key barrel are the induction coil used to wake up and read the immobiliser chip built into the key. If that is not working the car CANNOT start, as it won't get the 'release' code.

[doctle]

did you check for a spark? not all the slots on a relay plate are used

[306GTI]

did you check for a spark? not all the slots on a relay plate are used

The car is cranking but, there is no spark and no fuel in the cylinders.

[306GTI]

Quick update,

The injectors and coils are not receiving a pulse.

The car is cranking and the fuel pump is priming.

[xantia_v6]

That could be an immobiliser issue, or a lack of crankshaft sensor. Have you had a diagnostics session?

[306GTI]

That could be an immobiliser issue, or a lack of crankshaft sensor. Have you had a diagnostics session?

The auto electrician mentioned that was unable to do a diagnostics test as the ECU was not communicating with the scanner.

[306GTI]

The looks around the key barrel are the induction coil used to wake up and read the immobiliser chip built into the key. If that is not working the car CANNOT start, as it won't get the 'release' code.

Thank you for clarifying.

[ekjdm14]

That could be an immobiliser issue, or a lack of crankshaft sensor. Have you had a diagnostics session?

The auto electrician mentioned that was unable to do a diagnostics test as the ECU was not communicating with the scanner.

This could be why they called ECU. I bet it isn't the ECU itself though (unless battery was connected backwards at all, but then would probably blow a fuse before frying the brain IMO). First thing a good auto sparkie would do is check for power at the diagnostic socket. It's not unheard of for the fuse to this to be blown/missing for no apparent reason. Also depends what kit he was using, PSA cars are notorious for not wanting to "talk" to anything but Diagbox/Lexia/PP2000.

Also, I'd expect the immobiliser to not allow cranking so don't think it was immobiliser fault (you could confirm/squash this by taking the key blade out and trying to crank it with the transponder part a distance from the car. If it still cranks then disregard my thoughts, if it now doesn't turn then the immobiliser isn't the issue)

If you have a multimeter you can check for a pulse from the crank sensor, not sure of what range but you should see something flickering on the meter when you crank the engine.

[306GTI]

The car will crank with the transponder in the key removed.

Crank and cam angle sensors are good. Signal confirmed.

[xantia_v6]

The immobiliser won't stop the cranking or the fuel pump but will stop fuel injection, ignition and (I think) diagnostics communication. So an immobiliser fault seems most likely.

An immobiliser fault could be in the ECU, but could also be in the BSI, the transponder antenna, the key or the wiring.

Does the BSI show normal diagnostics?

[306GTI]

The immobiliser won't stop the cranking or the fuel pump but will stop fuel injection, ignition and (I think) diagnostics communication. So an immobiliser fault seems most likely.

An immobiliser fault could be in the ECU, but could also be in the BSI, the transponder antenna, the key or the wiring.

Does the BSI show normal diagnostics?

Thank you for the response.

I have read that the immobiliser is responsible for the injectors and the coils. I agree with what you have said because my fuel pump still primes.

You can crank the engine even if te ECU is not installed (plugged in).

I am not familiar with the term BSI. For me to answer your question you will need to explain.