legacycentral bbs

Dear all,

Hope you can give me some input on the following:

Recently on my trip to work my car started to run on three cylinders.
I needed the car that week so I made a few small trips with it afterwards. It ran most of the time on three cylinders, only around 2200rpm it started to run almost on 4 cylinders again, but never completely did it.

Also because my car was running rich already (before the 3 cylinder issue) I suspected the injectors.
I removed them and send them off for cleaning and testing.

They tested all oke, nothing wrong with them according to the mechanic.
I installed the injectors using new o-rings in the fuel rails. Mounted the fuel rails back on the car, connected everything back together and started testing.
In test mode everything oke, no leaks or whatever.

Then started the car, here’s what happens:

It starts immediately, revs up to 2700rpm, then after few seconds revs go down up to 400-500rpm, stumbles somewhat and engines dies.
I can keep it running with the help of some extra throttle, but engine runs rough and engine shakes.

Battery may not be 100% because it’s standing for a few weeks, but it starts and cranks good, so I think it has enough juice.
All other connections seem to be oke, no false air. Fuel pump is not too old (Walbro 255l/hr) and buzzes alright and you can feel pressure building up in the fuel lines when in test mode.

What can cause this problem?

Last Sunday I also removed the spark plugs to see what shape they’re in.
Didn’t have a helper to see if all of them sparks, but this is how they look like:

Cil1:


Cil2:


Cil3:


Cil4:


Spark plug no.3 is different looking at the white electrode, while the other are all black there.
What is indicating this?

Hope someone can help me out here a bit, hard to find the problem on this.
Especially the engine starting and dying on me as described above, keeps me puzzled.

Oh, no error codes whatsoever btw…

Bram

Cylinder 3 is dead. It does not appear that there has been any combustion going on in that cylinder. That spark plug looks almost brand new. How many miles are on the plugs?

I'd suggest double checking that you have spark on cylinder three. When you pulled cylinder 3 out did it smell like fuel?

The next step after verifying you have spark is to check for fuel.....if the plug didn't smell like fuel, trying swapping injectors with another cylinder. If still nothing, you may have an issue with the valve, valve springs, or cam.

I've checked the harness:

measuring resistance trigger wires for injector and coil, proved ok.
measuring voltage at injector and coil, proved ok, close to battery voltage.
measuring ground connection at coil to engine, proved ok (car has WRX coils modification btw)

Maybe coil or spark plug is broken, have to check for spark next.

Maybe tonight I can check this, otherwise next week.

gr. Bram

I agree with Josh, cyl 3 is dead. Do the easy things first, check for fuel and spark in #3. If good on both then you are looking at an internal issue but hopefully it doesn't get to that.

Best of luck, report back with what you find.

What is the WRX coil modification?

I know it may sound silly, but have you verified that the spark plug for #3 cylinder is actually good and will spark?

2.2TLegacy wrote:I agree with Josh, cyl 3 is dead. Do the easy things first, check for fuel and spark in #3. If good on both then you are looking at an internal issue but hopefully it doesn't get to that.

Best of luck, report back with what you find.

Removal of the original Legacy coils, removal of the ignitor and installing WRX coils that have the 3 pin connector.
See this Nasioc topic:
http://forums.nasioc.com/forums/showthr ... on+igniter

No possibility to check for spark this week, early next week I'll have an assistant

Bram

Well, some results eventually.

After some testing, measuring it eventually proved to be a corroded contact in one of my coil connetctors.
For some reason this connector was moist and one of three contacts very corroded.
Bummer to see this in such bad shape, but I found the problem and hopefully it will be back runiing on all four cilinders shortly
Need to find a new connector for this.

See pics:





Bram

Can you pull the pins out from the back side and clean the connector up at all?

Legacy777 wrote:Can you pull the pins out from the back side and clean the connector up at all?

Yes, that's quite easily. With a small screwdriver lift the tab a bit on the front of the connector and extract the pin.
I was lucky to have similar pins in my stock, so I crimped on a new connector and removed the old corroded one.

Anyway, tonight reinstalled the coil.

It runs on 4 cyl. now, but still not really nice.
After start up, it still climbs to about 2500 rpm, stays there , and then start dropping to 1000rpm and then drops to 500rpm when it really starts struggling (I shut it off then).
A few times, the ECS light came on, showing upon readout to be code 24 (bypass air control valve).
Following the troubleshooting guide evenytually showed that I have no voltage on pin 1 and 2 on ECU connector B125.

Between ECU B125 pin 2 and ground I should see 8-9V.
Between ECU B125 pin 1 and ground I should see 6-7V

I only see about 0,1 - 0,4V...
This should mean my ECU is broken and my bypass air control valve isn't properly controlled by the ECU.
The symptons of a faulty air control valve matches the symptons btw, so I may be on to something...

Bram

Is it possible for the primary side of coil to even cause just one cylinder to misfire?
The waste spark design employed in EJ22 uses two coils and fire in pairs, so wouldn't it misfire in pairs?

Yup.....a bad coil would cause two cylinders to be dead.

Legacy777 wrote:Yup.....a bad coil would cause two cylinders to be dead.

I've got the coil on plug set up, so one coil out means one cylinder not firing.

But anyway, after many weeks I got the car transported back home where I could finally do some good work on the car.
Working on it in dark wintertime on a cold and windy parking lot wasn't gonna make it.

So, I started first checking out the parts that I'd been working on.
My guess was that based on the symptons, I'd an air leak cause false air being sucked into the engine.

So, after removing some inlet parts and the fuel rails, I think I found my problem.
During the work I'd initially not installed the spacers that go underneath the fuel rails; I didn't bolt down everything in place really tight, and then installed these spacers.. Apparenty, they damage easily, look at the picture:



Well, injector would not have injected the fuel correctly and problably the seal wouldn't have been airtight. I don't feel too good making such a mistake, but hey, sometimes these things happen.

Now working on replacing those fuel lines and replacing my vf-11 turbo for a td-04. Hopefully with a fuel weeks I have a good running Sub again!
Remember those fuel rail spacers!

Bram

Well hopefully that was the problem and it runs properly now.