Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: david62 on 28 September 2009, 20:08:11

Title: my 1st omega
Post by: david62 on 28 September 2009, 20:08:11
just picked my 2000v 2.5cdx 65,000miles up..drove fine on way back 50miles..but came to junctions and stalled but always started ,car smelt like cats over working,done paper clip test and code 91 came up which i presume is something to do with o2 sensor? is this a replacement jobby or bad connections..any input from you guys would be of great help many thanx david..ps will post pics up asap of car :y
Title: Re: my 1st omega
Post by: rustym95 on 28 September 2009, 20:27:49
would change it and give car a full service best to be safe than sorry good luck hope yo have many years of driving to together  :y :y
Title: Re: my 1st omega
Post by: david62 on 28 September 2009, 21:40:31
thanx.. just another thought is there 2 lots of o2 sensors? if thats the case which 1 do i change or just do both?
Title: Re: my 1st omega
Post by: Welung666 on 28 September 2009, 21:51:12
Re-do the paperclip test! More likely a 19 not 91.... it is very rare lambdas fail and more likely the crank sensor with it just cutting out like that. A failed lambda would just cause over or under fueling.

Post all the codes you get from the paperclip test as that will help.
Title: Re: my 1st omega
Post by: david62 on 30 September 2009, 17:16:32
took car to mate who had a diagnostic tester and came up with gs sensor..changed that for vauxhall one and still same...took for test and wont rev above 3500-4000 revs just holds back and still wont idle...no faults on his tester...o hum..left it wiv him for a few days..determined to get to the bottom of this though..ty david :y
Title: Re: my 1st omega
Post by: rustym95 on 30 September 2009, 17:32:00
check your coil pack, take spark plug out rest it on side of engine (take rest of so engine dont start) see what colour it is if its a nice blue spark it ok if it is yellow or orange its a bad spark, coill packs will work even when they are going, check that out  :y
Title: Re: my 1st omega
Post by: CaptainZok on 30 September 2009, 17:33:55
Quote
check your coil pack, take spark plug out rest it on side of engine (take rest of so engine dont start) see what colour it is if its a nice blue spark it ok if it is yellow or orange its a bad spark, coill packs will work even when they are going, check that out  :y
Or do it properly using a test plug and firing the dis with Tech2/"My Naff Code Reader".
Title: Re: my 1st omega
Post by: rustym95 on 30 September 2009, 17:37:16
better to see it than read it do the old way. u see it not read it. :y
Title: Re: my 1st omega
Post by: david62 on 30 September 2009, 17:39:28
ill give him till 2morrow and if all else fails see if some1 on here would take a look for me..plzzzzzzzzz!!..am in hemel hempstead
Title: Re: my 1st omega
Post by: CaptainZok on 30 September 2009, 17:39:50
Quote
better to see it than read it do the old way. u see it not read it. :y
How is firing a plug in air "better" than testing the HT voltage to see if its adequate to spark under cylinder pressure?
Title: Re: my 1st omega
Post by: rustym95 on 30 September 2009, 17:43:58
not in the air on the side, earth'd,
Title: Re: my 1st omega
Post by: CaptainZok on 30 September 2009, 17:45:39
Quote
not in the air on the side, earth'd,
So how do you create this vacuum "on the side, earth'd" then?
Title: Re: my 1st omega
Post by: rustym95 on 30 September 2009, 17:51:09
what vac i coil pack what vac are uon about, just checking spark nothing els.
Title: Re: my 1st omega
Post by: david62 on 30 September 2009, 20:53:23
just so im prepared is there ne good mechanics round hemel hempstead way that may wana take a look at me mig..cheers
Title: Re: my 1st omega
Post by: rustym95 on 30 September 2009, 20:58:30
just try it it will work have done it loads of times can tell u lots, blue is good others on way out, i tryed it on tester said nothing wrong but tested it by eye sight and it was not good had red spark, got new 1 works 100 times better, put new 1 in nice blue spark tester did not work. :y
Title: Re: my 1st omega
Post by: david62 on 30 September 2009, 21:01:57
would this cause the idle prob aswell as the holding back?..cheers for yr help
Title: Re: my 1st omega
Post by: 3.2 manual on 30 September 2009, 21:09:27
might just be me being stupid..but doesnt a plug always fire under compression as there would be nothing to burn in a vacume?( except in the wasted spark principle) as used on some bikes when it fires on the exhaust stroke. is it a way of testing plugs?
Title: Re: my 1st omega
Post by: Kevin Wood on 30 September 2009, 21:55:28
Quote
might just be me being stupid..but doesnt a plug always fire under compression as there would be nothing to burn in a vacume?( except in the wasted spark principle) as used on some bikes when it fires on the exhaust stroke. is it a way of testing plugs?

Correct. The plug that does the work will be under pressure, meaning more volts are required.

Pre- 2.2/2.6/3.2 petrol Omegas are wasted spark. :y

Kevin
Title: Re: my 1st omega
Post by: CaptainZok on 30 September 2009, 22:07:05
Quote
Quote
might just be me being stupid..but doesnt a plug always fire under compression as there would be nothing to burn in a vacume?( except in the wasted spark principle) as used on some bikes when it fires on the exhaust stroke. is it a way of testing plugs?

Correct. The plug that does the work will be under pressure, meaning more volts are required.

Pre- 2.2/2.6/3.2 petrol Omegas are wasted spark. :y

Kevin
That's what I was trying to say earlier, hence grounding a plug isn't a good test for a spark and could be dangerous to boot.
Title: Re: my 1st omega
Post by: rustym95 on 01 October 2009, 08:29:03
according to vauxhall it is the only way to test if there is a good spark there is no pressure needed as the engine should be set not to start ie remove spack plug leads, the DIS module can be test by arange of testers but this only proves that there is volts and position of spark, as there is a out put of upwords of 50.000volts to generats the spark on on any given lead ecu will not know if it is working or not only that it has power. you can test spark by A removing a spark plug and testing it on the side of the engine or B removing the leads and using another spark plug on the side of the engine, DIS module fault when in fault are, ruf running on idle excessive shaking when over 3000 revs, backfiring, resulting in damaging the CAT, othere fault wich also if the spark plug leads or spark plugs are damaged due to were and tear will result in same manner, DIS module should be replace with in a 4years of daily use. there are two types Bosh or SIEMENS, Bosh last longer that Siemens and have life time of upto 6years. this is quoted by mec at Vauxhall when I had mine done. dose not matter what size engine as DIS is used on all ECU engines. :y
Title: Re: my 1st omega
Post by: david62 on 02 October 2009, 08:18:09
hopefully gona try coil pack this morn when vaux deliver...still no takers on looking at me car then if this dont work? :'(....david
Title: Re: my 1st omega
Post by: Andy H on 02 October 2009, 10:46:44
Quote
Quote
Quote
might just be me being stupid..but doesnt a plug always fire under compression as there would be nothing to burn in a vacume?( except in the wasted spark principle) as used on some bikes when it fires on the exhaust stroke. is it a way of testing plugs?

Correct. The plug that does the work will be under pressure, meaning more volts are required.

Pre- 2.2/2.6/3.2 petrol Omegas are wasted spark. :y

Kevin
That's what I was trying to say earlier, hence grounding a plug isn't a good test for a spark and could be dangerous to boot.
With non-wasted spark ignition one end of the high tension coil is grounded & the other is connected to the centre electrode on the spark plug. Assuming that the body of the spark plug is grounded then there is one small gap for the spark to jump. The voltage generated by the ignition coil will rise until it is high enough to generate a spark. If the spark plug body is not grounded then the voltage required to jump from the centre electrode to the body and then from the body to something grounded (probably the idiot holding it ::)) can be high enough to destroy the ignition coil (or a heart pacemaker).

With wasted spark ignition each coil serves two spark plugs. The high tension coil is not grounded, one end goes to the centre electrode of one spark plug and the other end to another spark plug. The cylinder that is not firing is at low(ish) pressure (it should be at the top of the exhaust stroke) the other should have compressed fuel/air mix waiting to be fired. The spark has to jump two gaps but as Kevin has pointed out a high voltage is required for the ignition spark and only a low voltage for the wasted spark.

Both types of ignition rely on there being a high tension circuit. If you lose that circuit (due to the plugs NOT being grounded or through damaged or disconnected leads) then the voltages generated get much higher than they should be which is dangerous and is likely to destroy the insulation in the DIS / coil pack.
Title: Re: my 1st omega
Post by: I_want_an_Omega on 02 October 2009, 13:40:41
well articulated
Title: Re: my 1st omega
Post by: david62 on 02 October 2009, 14:34:35
ave tried coil pack and still the same so back to square one...any good mechanics on ere care to take a look asap plzzzzz :y..[just to update ave tried gs sensor,airflow meter,egr valve and icv aswell..tech test and no faults coming up]now have no hair left to pull so be gratefull if some-one can ave a look..thanx david
Title: Re: my 1st omega
Post by: david62 on 02 October 2009, 18:30:18
think i might of sussed it.took rear tailpipe off which looked the wrong one to me[only single pipe outlet instead of twin?]found blocked up which in turn has blocked cats.started car with them off briefly and ran fine.parts coming in morn about £350 all in inc gaskets n clamps.think its worth it has only paid £280 for car? keeping fingers and toes crossed for bout lunch time tomorrow..will let you know and post pics if works ;)
Title: Re: my 1st omega
Post by: jonnycool on 02 October 2009, 18:38:40
2.5's have the single tailpipe as far as I know, only the 3 litre and 3.2 litre cars have the twin, but well done for spotting the blockage, hopefully it's sorted now :y :y
Title: Re: my 1st omega
Post by: david62 on 03 October 2009, 23:33:10
hi just an update on me car.now revs to red line and not stalling but wait for this....just a slight misfire/holding back and idle fluctuates at sometimes 1400..1000...600 if you blip throttle it will steady itself..noticed on icv that there were burrs on bit that moves cud these be stopping it from doin its job properly? also the big valve infront of the cam covers[in pipe for egr circuit] when you take rubber pipe off is make an awful noise all the time but my mates is quiet...is there ne one close to me who like to take a look for me plz has im running of ideas etc..thanx david
Title: Re: my 1st omega
Post by: 3.2 manual on 06 October 2009, 17:37:29
constipation for cars, i bet thats a relief now its gone, egr can cause a lot of idling problems, cause they are a crap idea, have heard they can be soaked in redex or blanked off, dont know if this can be done on the omega.