Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Linixs on 14 July 2014, 16:52:41
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Hi to All
I have the Omega 2.2 sport Auto
When my car is cold it fires up instantly. . But it backfires bad through the intake.. and I can't rev the engine. And then it blows its self off ..stops..
I have to keep starting it and gradually i get to be able to rev it..
Then once warm its pretty good. .
It runs quite well I get 29mpg around town witch is quite good for a 2.2.
Sometimes if I stop say at a shop when I restart it, it runs rough. .
So I turn it off then start it again and its fine.
If I disconnect the MAF sensor it gets a tiny bit better but Bearley noticeable. .till next time its cold.
If I disconnect the ignition coil pack then reconnect it seems better.. till next time its cold.
Is this a brake down of the MAF sensor?
Or a brake down of the ignition coil pack?
Or something like spark plugs?
Or other sensors?
Im stumped!
I Would be most grateful for any help. .
Thanks
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At risk of being depressing ::) could that be a sign of impending headgasket failure... any warning lights on? Any other messages on the display? Have you had the fault codes read to see if there's anything amiss electronically :-\
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To get an intake backfire like that, an inlet valve needs to be open when the spark plug fires, which sounds like either the valve timing is way out in which case the valves/pistons would probably be meeting :( or something is making the ignition timing occur at totally the wrong time, but only when cold.
The only things that control ignition timing are crank and cam sensors ... could one of those be faulty but only when cold ???
Ignition timing would also explain the lack of power when cold ...... but the question is ... why ??
I know too little about the 4 pot to answer my own questions ..... :(
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Really you need to get the ECU codes read. Try PMing Jimbob, he's around your way...
As well as codes, you need Live Data for MAF, trims, CTS, TPS and throttle feedback for starters
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May be a good idea to put the car intake back to how it was until you have got it sorted :y
http://www.omegaowners.com/forum/index.php?topic=124140.msg1580949#msg1580949
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Hi.. thanks for your help. No warning lights or messages on the dash at all.. the car was ace till I left it SORN off road for about 6 months. . If that helps
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Hi Bigtime.. dun that. Made no odds :y
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Would just leaving your car stud still cause these problems?
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Best bet is to do what TB suggested and contact this member to get a code reader on the car :y
http://www.omegaowners.com/forum/index.php?action=profile;u=74
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Was the "performance" filter an oiled type?
BTW, no air filter will beat the original GM one for performance on an Omega ;)
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No it was a K&N type filter. . But not by that company
I would add a pic but don't know how. ..
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That's a relief :)
Lets see whats what once its been on a reader.
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Is this going to cost me a fortune, do you reckon?
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Is this going to cost me a fortune, do you reckon?
PM Jimbob, or any other member in the region with code reading facilities, and see what he says ;)
Personally, I charge a tenner to read all ECUs on an Omega normally, but then I have the full dealer level diagnostics kit. I can't imagine any member (not running a garage business) would charge more...
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I bought a code reader and the code I got was
(1)P0650 - malfunction indicator lamp (mil) control circuit
Which is the engine service light is faulty. . True its not working. .
(2)P1781 engine torque signal circuit..
Gear box problem I believe. . Not sure on that one
(3)P0141 O2 sensor heater circuit bank 1 sensor 2..
A oxygen sensor on the exhaust just after the manifold..
On checking it out.. I was amazed to find it loose rattling around. . Cleaned and retightened.
Thats all the codes.. yet if the MAF sensor is fitted while starting the car from cold its very sloppy.. back firing.. cutting out.. disconnect it and car runs good.. yet no fault code... help
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New Maf sensor from Vauxhall then :y
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You reckon?
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If unplugging it makes the fault disappear, then it stands to reason that the thing you unplugged is faulty... :y
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Ok.. fair enough. . Thanks :y
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Ive had a code reader on it and it gives
P0170 fuel trim bank 1
P0141 O2 sensor heater circuit bank 1 sensor 2
P0036 HO2S heater control circuit bank 1 sensor 2
The P0141 O2 sensor heater circuit bank 1 sensor 2. .
I believe to be the exhaust senser.
When I checked it out it was so loose it was wobbling about. I took it out cleaned it and reinstalled, but its possible its broken with the vibrating it must of dun while being loose.
The P0036 is allso something to do with the exhaust senser I believe. .
The P0170 fuel trim bank 1. . Thats the MAF sensor I believe. .
All these parts expensive for my model of car, so I'd like to get it right as soon as possible to save wasting money So here's my question? Which sensor would you say is the 1 causing the missfire? Which one needs replacing? Thanks for any help
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