Immobilizer issues - Still starts eventually

[ettla]

Hello!

As you can see i have a Opel Omega 3.0 MV6 Auto.
The problem is that the car starts only momentarily for one second or so before the engine light starts blinking, but eventually after turning the key until the engine cranks and starts momentarily atleast a couple of times, but sometimes up to 100 times! THEN the car suddenly starts and runs just fine until you turn it off again and you have to do the same procedure all over again... 

The problem first appeared after the alternator died and the engine stalled because of low voltage. I replaced the alternator and charged the battery and tried to start the engine again, and this happened.

If you turn the key fast enough the engine starts for a second but immedietly cuts out when the engine light starts blinking and the immobilizer kicks in!
If you turn the key slowly to "ignition on" position and let the engine light first light up and then start to blink BEFORE you begin cranking, the engine only cranks but does not give any sign of fuel or ignition.
If you turn the key fast a couple of times (can be up to 50-100 tries) the car eventually starts and runs completely normal.

I think this is an immobilzer related issue because i have read that a blinking engine management light means that the immobilizer has kicked in.

I don't know where to begin looking, its a really strange behavior and i cant seem to wrap my head around it. I hope some of you guys on this forum could help me to find what is causing this issue!

I am thinking of uploading a video of me trying to start it but i am not sure if i am patient or lucky enough to get it started on video 

[biggriffin]

I would replace,the crank sensor. Doubtful it's the immobilizer

[johnnydog]

I agree with changing the crank sensor. Had similar issues with one of mine many years ago which was the crank sensor.

[TheBoy]

Hmmm, I think it could be immobilser, not crank sensor

Does it have the reddish dome under mirror?

[Andy B]

I agree with Jamie  Had a new key coded for SWMBO Astra, and that did the same as the OP's car ie start & then die. New chip in the key & it was away.

(I know it's a different setup though on an early infrared alarm Omega)

[ettla]

I agree with changing the crank sensor. Had similar issues with one of mine many years ago which was the crank sensor.

Are you guys sure about the cranksensor? What about the blinking engine light, i thought that was immobilizer specific notification. Can anyone confirm this blinking light being immobilizer specific or not? Thanks for the fast responses! Appreciate it, i acctually ordered a crank sensor from ebay today, was only 10 dollars. I dont know what i would do without you guys, My next move was to check all grounds or something 

[Andy B]

...
i acctually ordered a crank sensor from ebay today, was only 10 dollars. I dont know what i would do without you guys, My next move was to check all grounds or  .....

Generic crank shaft sensors often quickly fail 

[ettla]

Hmmm, I think it could be immobilser, not crank sensor

Does it have the reddish dome under mirror?

I agree with Jamie  Had a new key coded for SWMBO Astra, and that did the same as the OP's car ie start & then die. New chip in the key & it was away.

(I know it's a different setup though on an early infrared alarm Omega)

Thanks for replying! I only have one key to the car, it looks like this
The key has one of those small immobilizer chips in it, it is there, not missing or anything. But it seems to work only when it wants too?

As for the reddish dome, i dont think i have it, i dont have the car at my house right now so i cant check immedietly.
But i do not have a remote locking key available, erlier owners maybe had it, i didn't get one when i bought the car.
What did you mean with the reddish dome, what does it make of a diffrence?

As you said Andy, i have the same issue as you had with your car, when it starts only for a sec or so and then cuts out. But did you ever get it going by just turning and turning until it started and ran just fine until you shut it off again?

This makes me think that my battery may be bad or that there is some ground loose somewhere... What is your opinion on that?

...
i acctually ordered a crank sensor from ebay today, was only 10 dollars. I dont know what i would do without you guys, My next move was to check all grounds or  .....

Generic crank shaft sensors often quickly fail 

Oh well, i looked into it and it seems that i have ordered the wrong one too? there are 2 different types on ebay.
I ordered the first one of these 2:
10 dollars
30 dollars approx

i bought the cheapest one, thought i could not lose anything for 10 bucks and i didnt realize that it was different models... the screwhole was on the other side on the first one 
But i will wait to see if it fits anyway. Thanks for the tip, maybe i should buy a bosch of the right type instead? 

[Andy B]

...
As you said Andy, i have the same issue as you had with your car, when it starts only for a sec or so and then cuts out. But did you ever get it going by just turning and turning until it started and ran just fine until you shut it off again?

I only saw the fault when the dealer was programming the new key, the chip was duff, so he fitted another & all was sorted.

This makes me think that my battery may be bad or that there is some ground loose somewhere... What is your opinion on that?
...

Sorry, don't know 

[Andy B]

.....
What did you mean with the reddish dome, what does it make of a diffrence? ....

very early cars had a separate remote fob instead of built into the key which used infra red (not radio frequency) which had a receiver on the trim around the sunroof open/close dial

[TheBoy]

I was just trying to clarify if yours has the IR or RF system, as 95 should be IR, but 96 models were sold from midway through 95. 96 models are RF.

The fob bit, are both buttons the same size?  To be absolutely certain, can you post the last letter of you VIN (not the last number)

[ettla]

Ok Andy, but thank you very much for sharing your knowledge, atleast im not alone and that is one step ahead m8!
As for the fob, i dont acctually have the keyfob for remote lock/unlock of the car, i only have the manual key with the immo chip in it. But i took a picture inside my car to show you that i have what i think is the ir reciever "dome" you guys are talking about!



An answer to you TheBoy is also that i dont acctually have the "Fob" bit of the key, i only have the key part, but i think i have the ir system, what difference does it make for troubleshooting, i know it may be too complicated for me to understand, but i am open for anything!

HERE IS A VIDEO OF MY PROBLEM:
https://youtu.be/v6yIqo2znmY

[johnnydog]

Maybe totally unrelated to your problem, but years ago, I had a problem with a 3.2 where it would crank, and the engine would fire and run for a second - no longer, and then cut out. The spanner light would be blinking and the engine management light was on. Turned out it was the engine ecu which had been 'spiked' and fried itself. Not wanting to be alarmist, but with your alternator failing, could it be worth checking that the regulator hasn't caused any issues by any possible surges of power?
Not an electrical expert - I'm sure this possibity will soon be discussed!

[dbug]

Had similar on my old Elite, car would fire up and immediately stall, with flashing spanner light.

Try starting it with the MAF disconnected - mine fired and ran ok.  Replaced MAF, no further issues 

[ettla]

Maybe totally unrelated to your problem, but years ago, I had a problem with a 3.2 where it would crank, and the engine would fire and run for a second - no longer, and then cut out. The spanner light would be blinking and the engine management light was on. Turned out it was the engine ecu which had been 'spiked' and fried itself. Not wanting to be alarmist, but with your alternator failing, could it be worth checking that the regulator hasn't caused any issues by any possible surges of power?
Not an electrical expert - I'm sure this possibity will soon be discussed!

Thanks for the reply! Acctually this could be it... It was specificcally the regulator that failed and it is after that the problems started, could totally be the case if the regulator failed letting the alternator send unregulated voltage through the whole system... But lets hope that something else fried, like a sensor or something in that neighbourhood. Would totally be the worst case scenario with the actual ECU being damaged. BUT Sometimes it starts! This is very strange.