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does any one know if a faultey egr valve could cause a car to missfire under reves and drop cylenders in and out at idle cheers rowan

What sort of vehicle are we talking about here?

I would say that there's more of an issue with the spark ignition system - I'd be checking any electronic modules if it's an older dizzy run engine

Cheers

Bennie

I had similar symptoms when 1 ignition lead was broken internally. Check all your leads resistance with a multimeter and wriggle them a bit as you check.

i have an l series with ej22 conversion have 4 brand new leads and am getting a good spark at all plugs have swaped around most of the sensors with spare ones i have and no change have cheacked compression and all around 175psi so all good and have also done a leak down test and all good when i remove the plugs they come out covered in soot as if it is over fueling which makes me wonder if it could be the egr valve or solenoid dooing strange things

EJ22 doesn't have an EGR valve, so I can only guess it's more a breakdown in electrical or plugs are failing. What sort of fuel you running in it and when was the last time it had an 'Upper Cylinder Clean' ?

swapped most of the sensors ....the O2 sensor is what is meant to trim the fuel to correct afr and ecu defaults to richer than laner when O2 sensor reading is not got. Have you swapped O2 sensor at all and for a known healthy one ? Tap into its end at the ecu and see if it at least gives variable readings??

just tried swapping over a couple of o2 sensors and still the same i havent done an upper cylinder clean on it before how do i do that

if i unplug the o2 sensor it runns exactly the same is that normal

made24x4 wrote:if i unplug the o2 sensor it runns exactly the same is that normal

made24x4 wrote:ej22 in l series when i pull one lead off the engine. It stops dead how ever yesterday it was fine and would still just run on 2 cylenders with 2 leads pulles off cant work out what has changed

keep all of your problems in one thread, it is way easier to keep track of what was solved and what wasn't

I think it may be time to check the codes if you can ...

showthread.php?t=14372

If not Subarino might be tempted to make a house call (won't be cheap but it will be worth it)

TOONGA

made24x4 wrote:if i unplug the o2 sensor it runns exactly the same is that normal

Gotta get to the bottom of the spark problem. Then look at things like the o2 sensor etc.

Check your codes, see if there's anything in there that comes up - could give you a clue. It won't tell you everything though. If an ignitor is on the way out I doubt that there's a code to show for that :\

Cheers

Bennie

made24x4 wrote:I havent done an upper cylinder clean on it before how do i do that

Buy a can from Subaru and follow the instructions on it. Real easy to do but make sure you do it outside and away from your house.

made24x4 wrote:if i unplug the o2 sensor it runns exactly the same is that normal

Unpluging it will make it go into 'Limp mode' which allows the car to get driven home or to the dealer. It will make the 'Check Engine' light to come on and leave error codes in the ECU. I would retrieve those and start from there.

Let us know what codes you get.

I am down in Duns giving a hand to try and find the problem.
Connecting the black plugs shows nothing on a globe we connected up (from the ECU check engine pin to GND), but i am wondering if the globe is ground switched (i guess this would kind of make sense seeing driving lights etc are). In which case i need to run the 12v to the globe and then ground to the computer.

can anyone confirm this? i dont want to put the 12v straight onto the computer without being sure incase i fry it

its a strange problem, seeing as pretty much all sensors have been switched around (we have my l series + a wrecking ej22 l series + an iprezza engine + a blown liberty engine to get stuff off), new leads and plugs and the wiring is based off my cut down which has been working in my car for almost a year...

Yes thats right. Connect one side of the globe (make sure its a low wattage globe) and connect the other side to the ECU pin. In a recent Brumby to WRX conversion I did, I wired the check engine light to the 'Lo Range' light because the gearbox no longer had lo range. All the lights in the dash are negatively switched because they get their power from the IGN power in the instrument cluster

RSR 555 wrote:Buy a can from Subaru and follow the instructions on it. Real easy to do but make sure you do it outside and away from your house.

Where is Disco ?? He nearly needed therapy after he used an upper engine cleaner in a can .....

Gannon wrote:Yes thats right. Connect one side of the globe (make sure its a low wattage globe) and connect the other side to the ECU pin. In a recent Brumby to WRX conversion I did, I wired the check engine light to the 'Lo Range' light because the gearbox no longer had lo range. All the lights in the dash are negatively switched because they get their power from the IGN power in the instrument cluster

Cheers Gannon. we still have had no joy on the light... i wired it up how i think it should be and we cant get it to turn on with the ignition or give any codes. (If we short circuit from the ecu end to GND the light comes on, so its definitely at the ECU end). we are using a small LED, so i dont think wattage could be the problem.
we are pretty much at a loss having spent another day going over it all...

what would be a cause of really black sooty sparkplugs?

all the plugs ? if the injectors are dirty they'll piddle and not spray for best atomisation and not burn the best - sooty plugs ? same likely if pump pressure not the best....can you feed the ECU a voltage of correct polarity and voltage to instruct ECU to go lean ? you know, bypass O2 sensor to see ??

MTB92 wrote:what would be a cause of really black sooty sparkplugs?

Dead o2 sensor - ECU goes into limp mode and runs a richer mix to keep things happy for the short term.

Cheers

Bennie

steptoe wrote:all the plugs ? if the injectors are dirty they'll piddle and not spray for best atomisation and not burn the best - sooty plugs ? same likely if pump pressure not the best....can you feed the ECU a voltage of correct polarity and voltage to instruct ECU to go lean ? you know, bypass O2 sensor to see ??

yep, all plugs (which are about 3 days old, with probably 8mins running time). we have tried 3 different sets of injectors, all with the same result. pump is about 8 months old, commodore type and there is no way there is a lack of fuel anyway.

Bennie, we have also tried another o2 sensor, that made no difference. i do like your idea of bypassing o2 sensor though steptoe. i will see if i can find what voltage it should be and just rig up my own circuit to it.

also would any of those problems above cause a random but regular misfire (as in its always there, but the misfire appears to be spread over all cylinders)?

think you will find 0.5 to 5.0 Volts is the range - and if you can give it the variation and watch as you do you may find the problem, maybe not if the O2 sensors are known to be working fine on other engines......