Non starting Vauxhall Omega - netcar
I have a year 2000 OMega 2.5 which is refuses to start on odd occasions. No throttle is applied during the starting attempt, so I don't see how it can be flooded. If left for 15 minutes it may start first turn, sometimes however, it won't start for longer periods. The battery is in very good condition and turns the engine normally, but no cylnders attempt to fire. Anyone else experienced this ? Any ideas ?
Non starting Vauxhall Omega - Deryck Tintagel
I had a similar problem just the once on my Vectra when it wouldn't start. A lot of cranking later it eventually started but I don't fully understand why this happened. I put it down to the immobiliser - you might try locking and unlocking with the keyfob as this may be linked to the immobiliser. Alternatively, you may have a problem with the pick-up coil around the lock barrel. You might try taking the steering column surround off and checking the connections. NOTE check with Vauxhall that this won't upset the immobiliser - I don't think that it will but I wouldn't want to be stranded.
Non starting Vauxhall Omega - netcar
I\'ve tried locking and unlocking using either key, but without much success. Today is a typical day, didn\'t start once, now started 1st turn on 5 differet occasions. I do occasionally get a series of 4 beeps which I believ is something to do with the alarm battery backup, I\'m going to try and locate the batteries and replace them in case there screwing things up.
Non starting Vauxhall Omega - Vin {P}
For the 4 beeps solution:
Non starting Vauxhall Omega - Dynamic Dave
Just following on from what Deryck said about the immobiliser, does the engine management light flash when it refuses to start? If so, then the ignition key hasn't recognised the chip inside the keyfob, hence the immobiliser isn't disarming. Try taking the key out the ignition lock and reinserting. Alternately try using the spare key for a while to see if the problem goes away.

If the car has a factory fit alarm, then like Deryck, I had the same problem as him with my Vectra. Unlocked the car with the remote key, but car refused to start. Locked and unlocked doors with remote again and all was fine. It has only ever done it the once though, so I never made an issue of it.
Non starting Vauxhall Omega - MikeG
I have a year 2000 OMega 2.5 which is refuses to....

Well I thought it was just me - I have a 2000 Omega 2.5 with exactly the same problem - this started when the car was 2 years old and I have had it back to Vauxhall on a number of occasions. They have indicated that it starts perfectly (which it does!!). A couple of weeks ago after nearly an hour of not starting I decided to have a look under the bonnet. I found that there is a power distribution panel on top of the battery with a number of fused connectors These were corroded so I took them out and cleaned (this set the alarm off as you can imagine) - however when the fuses were put back it started. I thought I had cracked it - but yesterday I had the problem all over again..... Have you had any luck in finally resolving the problem?
Non starting Vauxhall Omega - netcar
Still suffering the same problem, happened once yesterday, but now fine again.
Non starting Vauxhall Omega - smithi
Not sure if I am too late here. but I have a 99 2.5 omega. Similar symptoms at 3 years old for around 6 months on and off. Always started eventually.

After numerous visits to garages to see if there was any fault codes registered (Never was) it was diagnosed as the crankshaft sensor. This was circa £200, then replaced under warranty after 3 months. That was over a year ago and it is still running sweetly.
Non starting Vauxhall Omega - tall paul
many years ago my father had a vauxhall VX, auto, great motor but from time to time would not start, over the years i have had lots of vauxhalls and 2 cav's that i had experianced the same problem, the conditions were always the same, either the car had just done a very short trip or just been started and stopped to say move it up the drive, or it was in a hot summer, to my mind it always seemed to be a choke related problem and i could sometimes start it by flooring the accelerator and just keep turning the engine over, on one occasion i gave up after an hour and got the AA out the chap turned up and it started first pull !!.

Anyway i have a ford now and i don't have that problem, now i just have high maintenance costs !!!
Non starting Vauxhall Omega - MikeG
The conditions you describe do in fact match my experience now I think about it. On every occasion the problem has occured it has been either after just moving the car, or a short journey, and the latest occurence has been when the weather has been very warm - in fact the time it took me over an hour to get started was during the "heatwave" last week. I didn't think however there was such a thing as a "choke" on a fuel injected car, but I suppose there must be something similar.
Non starting Vauxhall Omega - SpamCan61 {P}
Similar problems have been discussed in the BR before; although not with Omegas; you may get some clues from the following:-

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