EJ22 Missing at idle

austcold · Post by **austcold** » Thu Feb 21, 2008 8:59 pm

The last month my EJ22 has been gradually getting a miss at idle, I though it was leaky and tired heads, so I replaced the heads with reconditioned ones. It runs well with more power but the missing at has not gone.

I have measured the spark leads and they tested fine but I have some new ones on order anyway, I have replaced the coil pack around 18months.

The catalitic converter rattles on bumpy roads so I think its broken inside, could that cause the missing at idle?

? Could a Fuel Injector cause this to ?

I have unplugged the O2 sensor and that does not make a difference!

SuBaRiNo · Post by **SuBaRiNo** » Thu Feb 21, 2008 9:49 pm

Have you tried un-plugging each injector one at a time to see if it makes any difference. If a particular cylinder is at fault then the problem one should not effect the way it is idling.

This will rule out a LOT of things and if one particular cylinder makes no difference when you unplug the injector then you can narrow it down to only something related to that.

Dave

AlpineRaven · Post by **AlpineRaven** » Thu Feb 21, 2008 9:54 pm

Tension leads are common problem - even the tester does show correct reading but it doesn't really always does.
Coil Pack - Was it missing still before and after installed it? is it 2nd hand or new?

Catalytic Converter - Can be broken up and normally if its beyond 200,000kms they're no good anyway, expensive to replace from Subaru. I suspect it would be around approx $400 after market... Another thing I can point out - if the converter was all broken up inside you would have power gain not idling problem but you might notice rpm drop and go up and down... ie... 800rpm then up to 1000 rpm then down to 800 rpm because the computer thinks its idling too fast or slow... I dont know if it could happen with Subaru?

Fuel Injector - That is another thing - could be half flowed while idling but in full load ie. 2000 rpm is fine - could be flat spot, get injector cleaner and give it a try if it does improve a bit then you would know that they'll need cleaning - my good advice is use high octane and injector cleaner and go for a long constant drive.

O2 sensor has nothing to do with idle or idle speed etc but does give fuel mix ratio.

Other thing might point is the MAF sensor just behind the airbox inside the square looking thing - clean it with contact cleaner or pour metho on it and do not touch it... I had a flat spot between 2400 - 3200 rpm (where I had no power at that rev range as power would loose - turns out that MAF sensor was dirty - after clean it up it was better/solved.)

What happened and why did you replace the heads?
Cheers
AP

AlpineRaven · Post by **AlpineRaven** » Thu Feb 21, 2008 9:57 pm

SuBaRiNo wrote:Have you tried un-plugging each injector one at a time to see if it makes any difference. If a particular cylinder is at fault then the problem one should not effect the way it is idling.

This will rule out a LOT of things and if one particular cylinder makes no difference when you unplug the injector then you can narrow it down to only something related to that.

Dave

Yeah I would un-plug each injector and see if it does make a difference then it might point which one it could be - there is a clip on the injector's end that you can pull off with screw driver.
Cheers
AP

austcold · Post by **austcold** » Thu Feb 21, 2008 10:41 pm

Coil Pack was new about 18months ago with leads.

I have unplugged the injectors one by one but think I need to spend some more time testing as I did suspect a smoother 3 cylinder fire with on one injector.

I have alway's replaced parts with new ones if available, reconditioned the heads becouse they have done at least 250k, have noticed that the intake port on the old heads had a fair bit of emision crap in there and also on the injectors, caused from leaking valves.

I keep thinking it is dirty or a faulty injector but the Redex injector cleaner clear does not seem to improve it.

Is there a better injector cleaner available that I could run the car on straight.

SuBaRiNo · Post by **SuBaRiNo** » Fri Feb 22, 2008 7:41 pm

Best and really the only one to get your injectors clean is to remove them and get them cleaned and pressure tested properly by a mechanic.

if there is a spec of sand or something in an injector than no amount of clean will get it out.

I would get it done properly... if you remove them yourself it wont be very expensive.

Dave

AndrewT · Post by **AndrewT** » Fri Feb 22, 2008 8:28 pm

Note that it's easier to remove the part of the fuel rail which has the two injectors on it on both sides. Just give these to an injector place and let them take them off / put them back on again. Make sure they put new o-rings in.
Seems to be getting expensive to do this....I know AdamB has been ringing all over Perth recently and the price is about $30 per injector.
The place we were using here has now closed down

austcold · Post by **austcold** » Fri Feb 22, 2008 11:49 pm

Thanks for that, Im going to take it into someone next week who does ultra sonic injector cleaning and testing, they also have a scan tool to make sure the computer is happy.

I have now changed the leads and that confirmed that it was'nt them, but I am confident now that it is dirty injectors as it is not noticable when driving, and it idles smooth on a cold start up and for the first three seconds on a hot start.

austcold · Post by **austcold** » Mon Feb 25, 2008 8:19 pm

Stopped in at Sunspares Subaru at Yandina, Qld today to get a replacement Air Cond thermo fan as the old one is dead. I asked them about the injector cleaning and they said they have never had to have this done and that they just use a can of genuine Subaru Upper Engine Cleaner.

So I purchased a can and followed the directions on it, and it worked a treat as the miss at Idle it almost unoticable and it does say on the can that extremely dirty systems may require re-application. So i will get another can see how that goes.

Matatak · Post by **Matatak** » Mon Feb 25, 2008 8:37 pm

u might find it'll come back tho.

and it will do nothing for ur injectors dude. ya dont put it in ya fuel rails so it wont touch the injectors.

austcold · Post by **austcold** » Mon Feb 25, 2008 8:48 pm

Know what your saying, but they use it on every service as directed on the can and so do Subaru and they reckon that it is very rare that they have problems with injectors. I was convenced on getting the ultra sonic cleaning and new seals its just for the small cost of a can I gave it go, and I am very impressed with the results. Time will tell now.

Matatak · Post by **Matatak** » Mon Feb 25, 2008 8:55 pm

it may have actually helped you as reading back on what was suggested noone has mentioned the throttle body and cleaning it out. which the Engine Cleaner wuld of got to and cleaned up a bit.

if that was gummed up the butterfly when off the throttle can cause a Misfire and poor idling but is alright when it is opened.

did u ever get any stalling?

also on another note. how is the smell of the Engine cleaner

very potent and disgusting stuff LOL

austcold · Post by **austcold** » Fri Feb 29, 2008 9:18 pm

Rarely would stall but the miss at idle is that promonant its like a dodgy lead but fine under load, you could raise the rev's in neutural and could tell that it was still there when it flattened out. Un-noticable under load.

Have now run another can of Upper Engine Cleaner through but still have that miss, I have just done 1800km in the last 7 day's and it's running awsome with over 10km's to the litre on highway with air-con and two big hill climbs and using all the power it had at times.

So it did'nt just need a good blast with the cleaners, looks like Ultra Sonic Injector Cleaning and or Throttle body cleaning.

? I guess I should give the throttle body a scrub up first since its cheaper.

austcold · Post by **austcold** » Fri Feb 29, 2008 9:20 pm

I do have another throttle body, maybe i should change it over and try that?

Matatak · Post by **Matatak** » Fri Feb 29, 2008 9:43 pm

nah ud only need to clean urs out.

but if its happening when u hold the revs higher...then it wont be that.

if it runs fine under load i wuldnt expect it to be the Injectors.

sounds like the mixtures are screwed up abit.

IAC (Idle Air Control Valve) possibly?

austcold · Post by **austcold** » Sat Mar 01, 2008 9:51 am

Wel I cleaned up the throttle body and no change, I cleaned up a different throttle body and then fitted it, and still no change. I think we can eliminate the throttle body.

Yes I can tell that the miss is there at 1500 or 2000rpm but is very slight, much more promenant at idle.

It must be injectors, there was a lot of crap in the manafold and on the injectors and the cleaners made a difference.

AndrewT · Post by **AndrewT** » Wed Mar 19, 2008 9:18 am

Definitely get the injectors cleaned and flow tested professionally. I am not a Subuaru wrecker but strangely I have seen several examples of this instantly fixing problems similar to yours. Even if it doesn't fix the problem it will still benefit you.

marshy · Post by **marshy** » Fri Mar 28, 2008 7:38 pm

How th idle go Austcold? Liberty injectors rarely need cleaning.
You could have a problem with a lifter/valve , even though its runs good up top.