Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Malcolm_D on 29 December 2010, 09:27:28
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98 V6 2.5 Elite. Scuttle leaked, water in plug wells 4 and 6 causing significant misfire, removed leads and plugs - cleaned and put back on after checking coil pack. All were replaced last year so thought they would be OK. Reassembled but will not fire up :(.
Petrol getting through, engine turning over fine but not catching. Even if some of the leads/plugs were done for I would expect it to start amd misfire leading me to suspect the multi socket connections above the coil pack, have checked and re-checked and appear to be OK.
Next step? New leads first, possibly plugs to eliminate these? And after that?
I would immediately suspect the crank shaft sensor except that this was also replaced last year :( :( :(.
Advice and suggestions (polite ones ;)) please.
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checking for a fault code would the be first & easiest thing to do, 19 doesn't light the EML
Was your crank sensor a real Vauxhall Bosch part or a generic? :y
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Read lots about the paper clip method for fault codes but never done it - will look for the guide. Not sure about the sensor, the garage fitted it, I would suspect that it is a generic part.
Thanks for the swift reply. :y
While I am on, I need to confirm the lead order on the coil pack, it has numbers on it. With the conection on the left the top row is marked 5 3 1, and the bottom row (nearest the engine) is 2 6 4, does this sound right?
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Read lots about the paper clip method for fault codes but never done it - will look for the guide. Not sure about the sensor, the garage fitted it, I would suspect that it is a generic part......
Paper clip is here
http://www.omegaowners.com/forum/YaBB.pl?num=1189022687
A crank sensor from Vauxhall is around £50
Omega Part Number Retail Price Normal Trade Trade Club
Crankshaft sensors
2.0 16v to 14194716 90458251 £60.50 £54.46 £47.10
U25TD/X25TD 90487810 £98.50 £88.65 £76.94
2.5 (early models) 90492006 £83.50 £75.15 £65.12
2.5 (later models) 90492061 £61.50 £55.36 £47.88
2.0 8v 90493864 £60.50 £54.46 £47.10
2.0DTi/2.2DTi 90540188 £37.75 £33.98 £29.40
2.6/3.0/3.2 90540743 £55.00 £49.56 £42.63
2.0 16v from 14194717/31000001 9174621 £36.60 £33.00 £28.47[/i]
Also, make sure the cable is routed away from the exhaust, or you'll be doing the job again. :y
While I am on, I need to confirm the lead order on the coil pack, it has numbers on it. With the conection on the left the top row is marked 5 3 1, and the bottom row (nearest the engine) is 2 6 4, does this sound right?
Yes! :y That's right. ;)
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Thanks Andy, will get on with the paperclip test straight away. :y
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Paperclip test results - 31 as expected, and 13 - O2 sensor 1 open circuit, are the only fault codes showing. This doesn't mean a great deal to me, would code 13 affect the engine starting?
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Paperclip test results - 31 as expected, and 13 - O2 sensor 1 open circuit, are the only fault codes showing. This doesn't mean a great deal to me, would code 13 affect the engine starting?
oxygen sensor is another term for lambda sensor (lives just behind the cat on the exhaust.
Sorry, I can't make any other suggestions for your none starting though. :(
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Thanks anyway, I will plod on and try the obvious. On the upside I do not need the car at the moment, as SHWMBO says - it is my 'hobby' car! :y
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An O2 sensor problem will not affect starting.
Does the fuel pump fire up during cranking?
I would suspect crank sensor, as the wiring can get brittle and it would have been disturbed during plug lead access.
Kevin
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I can see the logic in your diagnosis, and I agree, but wouldn't this result in a code 19 from the paperclip test?
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It is not unknown for a crank sensor to fail without throwing up a code 19 error.
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Pull out one of the plugs to confirm you are getting a spark.
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Pull out one of the plugs to confirm you are getting a spark.
I remember doing this years ago on a mk2 escort - remove plug reconnect HT lead and have the plug earthing to the block by physical contact, turn the engine over and observe spark if any?
Am I right in thinking that the crank sensor makes sure that the spark is provided at the right time to cause ignition? Hence if it is goosed then the engine will not fire up? :-?
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Am I right in thinking that the crank sensor makes sure that the spark is provided at the right time to cause ignition? Hence if it is goosed then the engine will not fire up? :-?
Correct! :y
re HT lead & spark plug. You're better off clamping a spare plug to something like the engine lift hook with a pair of mole/vise grips, that way you're not going to be trying to do it by hand and then getting 15000/20000 volts up your arm :o :y :y
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Thanks for the advice, it will be followed. ;)
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If all the conventional wisdom and troubleshooting fails, my car failed to start last year for about 2 months because there was a poor earth somewhere (sorry to be so vague). The car was cranking and showing a spark, fuel delivery etc but wouldn't fire up.
Does sound as though you may have disturbed crank sensor though, they're temperamental things
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Checked for strong spark as per advice, it is there so all points towards crank sensor, will remove it once I can get access to the passenger side - it is parked close to a wall at present! First job is to see a medic as I appear to have developed a broken wrist :o :o
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I've just re-read the whole thread and I don't see where anyone suggested that you should break your wrist.
This will of course make further attempts at repairing your fault more difficult.
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If it is disturbed wiring of the crank sensor you could try re-disturbing it. I believe that's what got me home from Greece in August - a good jiggle of the wires both ends and off we went. Finally replaced the sensor in October when she failed to start again.
However, if as you say your crank sensor was replaced recently I would have thought it unlikely that the wiring would have degraded so soon. Could still be a duff generic part though.
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However, if as you say your crank sensor was replaced recently I would have thought it unlikely that the wiring would have degraded so soon. .....
depends on where the wiring was routed ie away from the exhaust. ;)
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Surely you're not suggesting that a garage would do it any other way :o
Reminds me, I ought to get out and cut off the old sensor and plug one of these days ::)
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I've just re-read the whole thread and I don't see where anyone suggested that you should break your wrist.
This will of course make further attempts at repairing your fault more difficult.
Panic over, well about the wrist anyway! Went to the docs who suggested a problem with tendons - no idea why though, the goods news is that it has now improved dramatically :)
The bad news is that the 'outlaws' are staying for a few days and it is back to work on Tuesday so no time yet to check the condition of the sensor :-[ It will have to wait until the weekend I suppose. :y
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Well, it isn't the crankshaft sensor! Got it off, it is a genuine GM part and the cable does not look cooked. Replaced it anyway, just to eliminate the possibility and it made no difference - back to the drawing board.
Next step is to check the strength of the spark more closely - how strong should it be and should it be a regular spark? Will try to check as many leads as possible.
After that I don't know! :(