Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: amba on 30 August 2008, 13:21:06
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Just come home from France after driving over 2500 miles in 18 days without a hitch,car ran perfectly and was a pleasure to drive.
Since returning home have now got a intermitent miss fire which after checking with a mechanic friend diagnostic readout and reading previous threads on the forumwe are now of the strong opinion that it is the dispack,especially as plugs/leads/cam covers and gaskets were replaced several weeks earlier.
Rang VX and have been advised that engine could have 1 of 3 different dispacks fitted ???Is it possible to establish which sytle and model is fitted without a total removal of existing unit as was hoping to be able to go out later today and get a replacement and then fit on sunday,as with car in pieces have limited options for tracking down a replacement.
Any advise please .Thanks
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I thought there was only two types. The difference is the connector. On one it is oval and on the other it is square. You can only tell which one you have when you start stripping things out. It is a bugger to get at!
You can get original Bosch ones from your local spares place without having to go to Vauxhall. Strangely one type is £30 or £40 more than the other.
You could buy both and take the wrong one back or take a chance and buy the cheaper one with the sqaure connector first. It seems to be the more popular one
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Thanks for advise MarkG.
Remember doing the same with crank sensor..sure local Motor Factors told me they list 3..so if the only difference is the square or oval plug is it possible to see enough with scuttle etc removed as would like to try and source today ready for the skinned knuckles on Sunday
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I have an almost new one from the MV6 i'm breaking, It had a missfire when i picked it up so went and got 1. Square plug :y
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Thanks for kind offer JueV6.I was hoping to get things put back on Sunday,but as my local Motor Factor is unable to let me know if they have the correct 1 in stock until I remove the old 1,even with "next day delivery" won,t get yours till Tuesday at earliest,unless you fancy a trip to Kent ???
Drop me a pm with £££,s you are looking for and might take you up if other options fail.
Just would be good to know which one is needed without total removal.
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Hmmmm, migh be worng but, DIS packs rarely cause an intermittent miss fire!
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the one on this MV6 did MDTM, only missed on number 1 cyl too. On the way back from Croydon it cured itself for a while and then resumed it normal miss,
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the one on this MV6 did MDTM, only missed on number 1 cyl too. On the way back from Croydon it cured itself for a while and then resumed it normal miss,
Still dont beleave it.
When you consider each coil on a DIS pack feeds two plugs an th failure mechanisms involved!
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pm sent, amba
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Marks DTM Calib..the miss fire is more than just intermittent but with a big engine the missing seems less noticable than just 4 pots,if you know what I mean.Idle is slightly lumpy but when throttle is "blipped" the miss is quite noticeable.Was advised that wise not to drive as unburnt fuel in bore would start to damage valves..is this correct ??
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3 different types...early models 94/95 had a different dispack...than the later models...thought it was all year related though...98 likely to be the same as the dispack on any other 98...
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Marks DTM Calib..the miss fire is more than just intermittent but with a big engine the missing seems less noticable than just 4 pots,if you know what I mean.Idle is slightly lumpy but when throttle is "blipped" the miss is quite noticeable.Was advised that wise not to drive as unburnt fuel in bore would start to damage valves..is this correct ??
Unburnt fuel will damage the cats long term.
Would be very interested to hear how he tested it as the ECU wont store fault codes for this......and I know that its quite involved to confirm it (having done it myself afew times using Tech2 + some additional test kit).
I assume a few plug leads have been pulled to chek for oil in the plug wells (remember that assumption is the mother of all break ups :y)
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Plug lead from each side removed and are bone dry..if not I would be going mad by now as have had both cam covers off and on several times and all leaks are now cured.
He plugged a hand held "omnitech "into the socket by fuse box and it showed a sparking icon which was intermittent with engine running and on the basis that leads and plugs are both new(less than 3k)and car has just returned from 2.5k trip to France,disspack seemed the favourite.
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Plug lead from each side removed and are bone dry..if not I would be going mad by now as have had both cam covers off and on several times and all leaks are now cured.
He plugged a hand held "omnitech "into the socket by fuse box and it showed a sparking icon which was intermittent with engine running and on the basis that leads and plugs are both new(less than 3k)and car has just returned from 2.5k trip to France,disspack seemed the favourite.
Even more suspicous now as you can get no info about ignition secondaries via teh diag port on the 2.5 and 3.0 V6's.....
The only way to test it is to connect the plug leads to test plugs and fire the sparks individualy via tech 2....
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Machine was bringing up codes 42/43 and when engine was running it gave a definite "flash and then spark" against each port on the disspack icon with a missed flash every so often..he was certain fault lay with dispack.
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Even stranger......because 42 and 43 are not part of the Motronic 2.8.1 code set!
Further more, the live data only gives info on the primary windings and shows when the coils are loaded. However, this is not reliable data as it is not real time and only random snapshots so some do not get reported. All its actually indicating si when the ECU pulls the primary side of the coil to 0V!
So what I am saying is that yes, you might have a weak spark but, the tests done are
1) Inconclusive because at no point has the DIS been tested
2) Point at somebody using a scan tool they dont understand!
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Just on Mark's point, I have had the experience of a VX 'technician' giving a diagnosis of a fault from the result of his reading from a 'tech 2' unit, one hour later with the same 'tech 2' and the car had not moved, a very different reading and result was given by a second person. As luck would have it the second person was a friend and more experienced mechanic, his diagnosis turned out to be correct and only cost £50 to repair compaired with a few hundred by the first person.
regards
richard a
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Just a follow up from the problems I was having with a miss-fire,due to a suspected faulty diss-pack.
Many thanks to JueV6 for coming to the rescue and his kind delivery of a replacement all the way down to Kent.
After much cursing and bruised knuckles managed to get the old one off and lady luck was smiling on me as the replacement had the same oval plug as the original.After a close inspection of the original it appeared to have evidence of burning across the middle buldge and severe rusting on the end buldge.
More cursing but managed to get the replacement on and with much relief the engine started first turn and ticked over as before fault.Just come back from a 30 minute run and engine has not missed a beat so despite some reservations as to wetherdisspack was the fault all now seems to be resolved,but for those about to replace a disspack in the future find a friend with long fingers and slim arms.
Thanks again JueV6.