MULTI MISSFIRE ON IMPREZA STI 04 CAN ANYONE HELP ME
10 July 2007, 06:55 AM
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MULTI MISSFIRE ON IMPREZA STI 04 CAN ANYONE HELP ME
I HAVE GOT A MISSFIRE ON MY STI TYPE UK 04 REG IT IS COMING UP AS A MULTI MISSFIRE ON THE CODE READER? IT IS JUMPING BETWEEN ALL 4 CYLINDERS????(WHICH TAKES ME AWAY FROM THE COILS AS THEY MUST BE OK DO YOU THINK) AND ALSO THE EMMISIONS ARE SKY HIGH (RUNNING VERY RICH) I HAVE FITTED NEW PLUGS,MASS AIRFLOW METER,N/S CAM SHAFT SENSOR AND AIR FILTER.IT IS ONLY NOTICABLE WHEN CAR IS DRIVING AT 2000RPM OR LESS AS IT JUDDERS BUT ANY HIGHER AND IT SEEM OK AS IT GOES LIKE F*** .PLEASE HELP AS THIS IS DOING MY HEAD IN
THANKS IN ADVANCE
THANKS IN ADVANCE
10 July 2007, 08:26 AM
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Please don't shout, god its hard to read!
It does sound like you've changed a lot of things, it would help if you could post the 4 gas emissions, if its running that rich then I presume the exhaust is black?
Have you checked the fuel pressure, is it possible the vac line has come of the regulator so its very rich until the load gets close to atmospheric (and you run dangerously lean on boost!)
Simon
It does sound like you've changed a lot of things, it would help if you could post the 4 gas emissions, if its running that rich then I presume the exhaust is black?
Have you checked the fuel pressure, is it possible the vac line has come of the regulator so its very rich until the load gets close to atmospheric (and you run dangerously lean on boost!)
Simon
10 July 2007, 09:06 AM
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Should it not be driven then??
Please don't shout, god its hard to read!
It does sound like you've changed a lot of things, it would help if you could post the 4 gas emissions, if its running that rich then I presume the exhaust is black?
Have you checked the fuel pressure, is it possible the vac line has come of the regulator so its very rich until the load gets close to atmospheric (and you run dangerously lean on boost!)
Simon
It does sound like you've changed a lot of things, it would help if you could post the 4 gas emissions, if its running that rich then I presume the exhaust is black?
Have you checked the fuel pressure, is it possible the vac line has come of the regulator so its very rich until the load gets close to atmospheric (and you run dangerously lean on boost!)
Simon
yes the exhaust is black mate and emmision reading is 10%??????
where is the fuel pressure regulator
I have not got the readings at the moment but when you say (run dangerously lean on boost) can this cause major engine damage i know it can destroy the cat.Please advise if you can or anyone
Thanks
Ian
Last edited by morphy41; 10 July 2007 at 09:27 AM.
10 July 2007, 09:42 AM
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Hi Simon
yes the exhaust is black mate and emmision reading is 10%??????
where is the fuel pressure regulator
I have not got the readings at the moment but when you say (run dangerously lean on boost) can this cause major engine damage i know it can destroy the cat.Please advise if you can or anyone
Thanks
Ian
yes the exhaust is black mate and emmision reading is 10%??????
where is the fuel pressure regulator
I have not got the readings at the moment but when you say (run dangerously lean on boost) can this cause major engine damage i know it can destroy the cat.Please advise if you can or anyone
Thanks
Ian
10 July 2007, 11:04 AM
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Please help
Thanks
Ian
10 July 2007, 12:19 PM
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You haven't mentioned the lambda sensor. This is used to manage the fuelling at lower revs and can cause it to run very rich. Usually lambda problems clear higher up the rev range (I think lambda is generally used till about 4k - when it swaps to MAF readings alone as lambda readings becomes unreliable).
I'm no mechanic, so seek confirmation before checking this.
To be honest this one sounds nasty enough to get it into a specialist who could probably diagnose pretty quickly with DeltaDash - especially given that the mixture could be leaning out under boost, which is not good at all.
BTW - it's running rich that will damage the cats so the sooner you get it sorted the better to avoid cat failure (if you have any fitted).
I'm no mechanic, so seek confirmation before checking this.
To be honest this one sounds nasty enough to get it into a specialist who could probably diagnose pretty quickly with DeltaDash - especially given that the mixture could be leaning out under boost, which is not good at all.
BTW - it's running rich that will damage the cats so the sooner you get it sorted the better to avoid cat failure (if you have any fitted).
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10 July 2007, 01:43 PM
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I had missfire codes on my 02 but that was upto 2500 revs and because I had wild piper cams fitted - the over lap of the valves caused fuel/air down the exhaust unburnt. Do you know the mods to your car?
Mine also hunts/shakes a little below 2500 but once above, hold on for dear life!
I'd get it checked by a mapper maybe as they'll tell you whats going on - Bob at BR developments is an excellent chap, very very helpful.
Get it checked sooner rather than later as you'll not be doing your new plugs, bores/valves and exhaust system much good if she's running rich all the time.
Mine also hunts/shakes a little below 2500 but once above, hold on for dear life!
I'd get it checked by a mapper maybe as they'll tell you whats going on - Bob at BR developments is an excellent chap, very very helpful.
Get it checked sooner rather than later as you'll not be doing your new plugs, bores/valves and exhaust system much good if she's running rich all the time.
10 July 2007, 03:37 PM
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I had missfire codes on my 02 but that was upto 2500 revs and because I had wild piper cams fitted - the over lap of the valves caused fuel/air down the exhaust unburnt. Do you know the mods to your car?
Mine also hunts/shakes a little below 2500 but once above, hold on for dear life!
I'd get it checked by a mapper maybe as they'll tell you whats going on - Bob at BR developments is an excellent chap, very very helpful.
Get it checked sooner rather than later as you'll not be doing your new plugs, bores/valves and exhaust system much good if she's running rich all the time.
Mine also hunts/shakes a little below 2500 but once above, hold on for dear life!
I'd get it checked by a mapper maybe as they'll tell you whats going on - Bob at BR developments is an excellent chap, very very helpful.
Get it checked sooner rather than later as you'll not be doing your new plugs, bores/valves and exhaust system much good if she's running rich all the time.
Cheers
Ian
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