OP. Immobiliser fault should normally show as dead to the world at all times and no turning over.
Is that particular to this engine/van ?
Because on my iveco I have a dumb key for locking up when we are out swimming so no fear of getting it wet it has no immob chip in and the van will turn over till cows come home but will not fire.
I still think fuel.
If its key fault you'd see an imu error.
You got breakdown? Their kit should scan it to the point it should check all the systems not just engine ECU.
You need a leak off test doing.
Btw pulling injectors on these can be horrific. I've a couple of contacts for doing this.
Don't forget the immobiliser is also reliant on the key to work as that has the RFID chip in it. My non-diesel Citroen Picasso was playing up in a similar manner and it turned out the RFID chip in the key had been damaged. A new key was all it took - getting the dealer code etc needed to to allow someone to program a new key was a bit of a faff mind!
I had exactly the same symptom on a diesel renault car. It was the immobiliser. Only the main dealer had the tech to diagnose and sort it.
an immob usually isolates the fuel pump and ignition circuit. So it wouldnt catch, if it was immob related. Likewise if it is electrical.
Since we're straw polling i'm going with fuel related i.e the pump(s). Try and listen to them prime. You could even whip a fuel hose off and see. Could just be an airlock too.
To thise aying that the immob will not allow it to turn over, that may be right for some vehicles/man's. The laguna I mentioned on page 1 did in fact turn over and 'fire once' as per the OP description. Some how a small amount of fuel was getting in far enough to fire but then the fuel system was cut so not able to keep running.
More modern systems could be different, ie not allowing the ignition to crank it at all.
Just passing on my experience.
Remember this one? Well, after the van being immobile outside the house for weeks due to holidays and bad weather I finally managed to get someone out to have a look. The garage that does the MOT's recommended a local auto electrician. Apart from him smirking tabs in my van he was very good. After a good deal of investigation and head scratching he got it running by disconnecting the Mass Air Flow meter sensor. I am now going to buy an OE one (there are cheapo one's available which don't last long apparently) and sling it in. It's a piece of the proverbial to fit by the looks of it. If that doesn't work then it could be the ECU. Crossing my fingers it's not that. ££££
Remember this one? Well, after the van being immobile outside the house for weeks due to holidays and bad weather I finally managed to get someone out to have a look. The garage that does the MOT’s recommended a local auto electrician. Apart from him smirking tabs in my van he was very good. After a good deal of investigation and head scratching he got it running by disconnecting the Mass Air Flow meter sensor. I am now going to buy an OE one (there are cheapo one’s available which don’t last long apparently) and sling it in. It’s a piece of the proverbial to fit by the looks of it. If that doesn’t work then it could be the ECU. Crossing my fingers it’s not that. ££££
With modern cars they have so many systems that aim to make them run more efficiently and able to diagnose any issues that it is more often than not these systems that cause the faults.
