Wauxhall Omega B. HUGE start/RPM problem

[firewalk]

I own a 1999 model Wauxhall Omega B. Recently I’ve been having a problem: When idling, it can suddenly just die. This has gotten worse and worse over time. It’s also very hard to start! When I turn the key the starter turns the engine over, but it won’t give spark to any cylinder for perhaps 10 seconds. Then it gives spark, then not again. Engine tries to start, but it misfires badly and I get very bad ignition knock as the spark is coming at the wrong time! Sounds like the engine is about to destroy itself when trying to start, so At this point I don’t even want to try any more until I have this problem sorted. When trying to start, it takes so long that It almost drains the battery, which is brand new by the way.

Anyways, When i finally I get it started, then the engine will run perfectly.. until it stops, or I stop it and try to start it again.. Then same problem. Engine light is glowing constantly. I can’t rev it beyond 4500 rpm. I suppose that’s because it’s now in a “limp home mode” to protect the engine.

I’ve been searching the web, and I can’t seem to find any solution to this problem. From what I’ve been able to learn, It could indicate that the crank sensor is to blame.

But if it was the crank sensor, why would the engine run so smoothly while running? Why would I have such huge truble starting the engine when it runs OK when started.. ? That don’t make much sense to me.. I would think that the engine would misfire constantly if the camsensor were to blame?

Another thing:

Topic

[dreamer2355]

The best way of testing crank and cam sensors is to use a lab scope.

Is the CEL light on?

Also, if the vehicle dies, you are obviously missing spark or fuel so the next time it dies, see which one is not present.

This video from Eric will give you a starting point.

http://www.youtube.com/watch?v=FBUYs539 … t3EVppbf88

[firewalk]

Quoted From dreamer2355:

The best way of testing crank and cam sensors is to use a lab scope.

Is the CEL light on?

Also, if the vehicle dies, you are obviously missing spark or fuel so the next time it dies, see which one is not present.

This video from Eric will give you a starting point.

http://www.youtube.com/watch?v=FBUYs539 … t3EVppbf88

Watched the Video. However, There’s nothing mechanically wrong with it since it’s running perfectly once started. It’s getting fuel and spark, just not when trying to start. That’s what so puzzling. Why will it run, but not randomly miss when trying to start?

The CEL is on. We tried to test when trying to start, and figured out that it’s not giving spark to any cylinder during start. 10 secounds may go by and it only gives a few sparks to any random cylinder. Then suddenly it gives lots of spark, allthough not in the correct order, since it’s missfiring badly. We used a “test-lamp” between the sparkplugwire and the plug in order to confirm the absense of spark. Eventually, after cranking long enough it will finally start. But it’s very hard!

It seems it’s the same thing that happens when it suddenly dies. During Idle, when RPM get’s low, it stops giving spark.

I don’t have a lab scope : I’ll have to see if I can find one to borrow.

But I keep wondering: Is there any logic to why the crank sensor wouldn’t function at low rpm? If so that could explain this. Still, I find it weird. Should think it would get more inaccurate with higher RPMs instead..

[dreamer2355]

What is the code for the CEL?

[619DioFan]

Is this car same as an opel omega ? this sounds like a coil problem. does the car have one coil pack for all cylinders or a seperate coil for each ? can you pull any codes ? I would check the power leads going to the coil (s) and check the coil(s) resistance.

[firewalk]

Quoted From 619DioFan:

Is this car same as an opel omega ? this sounds like a coil problem. does the car have one coil pack for all cylinders or a seperate coil for each ? can you pull any codes ? I would check the power leads going to the coil (s) and check the coil(s) resistance.

Yes, it’s an Opel Omega / wauxhall Omega. It gives me code 0335 which is crank sensor. However, I’m not sure I can trust the Codes as it might give that code anyways when the engine is not running. And I’m unable to read the codes when the engine is running. (using the paperclip method). I really don’t think it’s a coil problem. Because as I said, once the engine is started it runs perfectly with no miss. I’ve had to replace coil packs on other cars and the sympthoms are always the same: stuttering and shaking of the engine, backfiring, loss of power and not running on all cylinders. Mine does none of that. it runs perfectly once started. It has full power, No missfiring once started. it’s just when starting it has this problem. : That’s why it’s so hard to diagnose.

Perhaps I’ll just have to try and replace the crank sensor. It’s a $150 part ( I live in Norway). So I’ll just have to pray it’s that. I haven’t found a scope to test it with, and a garage will charge me the same amount that a new sensor cost just to test the one I have so I might as well try a new one then.

I’m still puzzled by the relation between cam and crank sensor though. Do they work in harmony or do they perform different tasks? F.eks crank sensor for starting and cam sensor for running? that would explain this problem though. But I find that a bit strange…?

[firewalk]

It’s been sorted. I went and bought a new camsensor today. But before I installed it I took a look under the engine. Then I realised that one of the bolts holding the starter motor in place was a bit loose. Motor was still in place and I could not move it in any way. Still, I tightened it down and tried to start the engine and voila. Engine started right away, and CEL was gone too. Kind of weird, but as long as it works I’m happy. 🙂

Good thing I didn”t open the package with the new sensor. Now I can return it and get a refund. 🙂

[EricTheCarGuy]

Glad you got it sorted out, I was going to recommend looking for a simple solution before going to a complicated one and since you had a code for a crank sensor that would have been where I would have recommended you start. I suspect that the starter connection is an important ground connection, if there is a faulty ground on an engine it can cause all kinds of performance issues.

Thanks for using the ETCG forum and for posting your fix it will go on to help others.

[R-vin]

hi,
glad to know that your problem was a simple one and easily resolved….i own a 96 Omega B with the X20XEV engine and i had two major problems…1. the fuel pump…it would work and then not work…this was substituted with a pump from a toyota vehicle, though i never ran the tank below 20 liters for fear that the suction bag of the pump is not all the way to the bottom of the tank,,, i never got around to experimenting to see at what level i would stop receiving fuel…

2. when the timing belt was replaced, a dowell that is used to hold in the 10mm fastener for the front cover, is also used to centralise the cam sensor, i did not realise this and a few months down the road, i encountered a problem, it went into limp home mode, it was switched off and restarted, it was fine…the code for a faulty cam sensor was pulled, i bought one to replace it, and under removal i discovered the problem…also any speck of metal would be attracted to the small magnet of the sensor..if metal filings accumulate…it can cause sensor problems…

the crank sensor is used to give the computer the crank shaft speed, and the cam sensor is used to fine tune the ignition spark timing per cylinder and also is used in the computer processing to activate the injectors at the correct time…together with the ignition knock sensor to give the spark at the appropriate moment for best fuel economy and sometimes power also…

[Author]

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