WRX ignition coils on EJ22T ECU

[Legacy777]

Dave,

Try swapping coils around to see if the problem remains on the no 1 cyl or if it follows the coil.

[DaveK]

Swapped the 1 & 3 coils and no difference.

Pulled the plug on 1 and looked for cracks, none found.

Hrmmm. Only thing I can think of now is that maybe I've got a wonky injector on #1?

Dave

[Legacy777]

Yeah....you could try swapping injectors....

[cj91legss]

Dave, How's your progress?

[DaveK]

Dave, How's your progress?

I just turned the boost all the way down and have been driving it like that. Started up on the first try at 15 below in Steamboat Springs last weekend and its getting me back and forth from there and Denver without much trouble. Will probably dig into it further when it warms up in the spring.

For those interested in doing the coil swap, I suspect my issue is something other than the coils (had issue before, still have issue), so I wouldn't be scared to give it a try.

Dave

[cj91legss]

Just curious cuz im looking at pickig up some sti coils today for a killer deal

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[cj91legss]

And just got them. All 4 with 3 pigtails on a partial sti engine harness for (deals.....)

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[DaveK]

Long time no update. Been DD'ing the car for a while and ran into some engine bogging/bucking issues when trying to accelerate in the 2500rpm range. Did a seafoam treatment and that seemed to fix whatever was causing that issue (not sure I understand what it fixed....but it pulled smoother). But, the issue is now back, so a buddy showed me how to pull codes so I did that last night. Here's what I found:

12 starter switch - Abnormal signal emitted from starter switch
14 Injector #1 - Fuel injector inoperative (Abnormal signal emitted from monitor circuit)
22 Knock sensor - Abnormal voltage produced in knock sensor monitor circuit
23 Air flow sensor - Abnormal voltage input entered from air flow sensor
31 Throttle sensor - Abnormal voltage input entered from throttle sensor
49 Air flow sensor - Use of improper air flow sensor

So, I guess I have some work cut out for me, LOL!

The issue on #1 is something I noticed a while back and was actually what led to me attempting the WRX coil conversion which didn't seem to have any effect on things (either good or bad). The car seemed to idle on 3-cyl and when I disconnected the plug on that cyl, sometimes it would have no effect on the idle quality.

Looking at the list, I think this is going to be my plan of attack:

1) check grounds at battery and various spots around the engine bay
2) pick up a new knock sensor, found them for under $20 on amazon (#22060AA030)
3) pull MAF out and give it a good cleaning (it is a hitachi unit)
4) check the resistance of the different injectors

If that one injector doesn't check out, I'm wondering if it might be worth trying to swap the stock EJ22T 390cc injectors on to this motor (EJ20G). I have a set bolted up to another intake manifold, so trying those is basically free...if the o-rings look ok. Sort of wondering if that might help out with some of the idle issues, but assume that I won't be able to run as much boost. For now just interested in getting the driveability back to where it should be and if I can run ~10psi that'd be great for now.

Anybody have thoughts/recommendations/experiences worth tossing out there?

Thanks for reading!

Dave

[wtdash]

#1 - I 'd check continuity on the #1 injector - should be 11-12 ohms, I believe? I've had a few Subie injectors die.

#2- Replace Knock Sensor and reset ECU to see what codes come back.


The 360-370cc EJ22T injectors should work better w/the stock EJ22T ECU, IMHO. The 450cc/gray tops that come on the EJ20G are used a lot on here, but they're not optimum. According to JC/Legacy777 the EJ22T ECU runs the engine very rich, so the 450's don't help.

Just a heads up...in case it matters....If your EJ22T injectors are in a SOHC intake manifold, the SOHC IM won't fit your DOHC heads....and the fuel rails are different between SOHC and DOHC.....

Edit: But the injectors will interchange - 450cc gray will work in the stock EJ22T rails and vice versa.

TD

[DaveK]

Just a heads up...in case it matters....If your EJ22T injectors are in a SOHC intake manifold, it won't fit your DOHC heads....and the fuel rails are different between SOHC and DOHC.

Thanks for the heads up - guess I won't try pulling on out to see if it'll fit...but I'm slightly confused. If you can install the grey tops in the SOHC, why won't the pink tops swap into the DOHC? Just a matter of needing to order up some specific o-rings?

My SOHC intake manifold is complete, so I've got fuel rails, injectors, fuel lines, etc. Do I just have to swap the SOHC rails to be able to use the SOHC injectors?

Dave

[wtdash]

The 450cc grays in you DOHC will fit the EJ22T stock rails and vice versa. The injectors look completely different, but they will work 'as is', from what I"ve read on here.

See this THREAD and my post halfway down.

The pic doesn't include the 450cc gray tops, but the yellow 480cc look the same as the 450cc gray tops.


So just swap injectors.




TD

[DaveK]

Oh derp....totally read what you said in regards to the injectors being swapped vs. the manifolds as you typed. Time for coffee!

With my swap I kept the EJ22T harness but extended some wires so it would fit with the DOHC intake manifold.

Dave

[cj91legss]

I'm glad you got yours fired up tho. I basically did what you did, and I only got mine to run on 2 cyl. I tried and tried, then just gave up because of all the cranking and fuel getting in the cyl. I was afraid of hurting the oil. Oil change asap...

[DaveK]

Digging into the car now.

1) Pulled the element out of the MAF and one of the probes had a bit of gunk on it. Cleaned it off.
2) Pulled knock sensor out and the old one was cracked.
3) The wire going from knock sensor into the wiring harness is cracked right where the shielded wire starts...assuming that's a problem?

Edit: Did some searching on here and it seems like I can peel back the shield a little bit and add in some new wire.

Thanks,

Dave

[DaveK]

Success....and discovering teh fail.

First up the good - knock sensor wire shielding stripped back an inch and used a heat shrink connector to put it back together. Took a few minutes to monkey the new sensor into place, but a coat hanger and long screwdriver later, and it's all snugged up.

Second was the MAF - super easy, just three screws and a bottle of carb cleaner and it's looking nice and fresh.

Lastly I dug into the injectors. All of my pink top (spares) tested between 11 and 12 ohms. I only tested the grey tops on the passenger side as the front one was the cyl giving me weird issues. Front one tested at 135 ohms and the rear one tested at 11.5. So, I think I've found the culprit! Another interesting side note is that the injector seems to have lost its snap ridge so the injector plug just sits on it, it no longer snaps into place. Plug looks good, but can't really see the underside of the injector to confirm the ridge cracked off.

Now its decision time. Do I try to fine one grey top, or go through the hassle of swapping out all four injectors. The lazy in me says swap the one and call it good. The 'I want this thing to run and idle well' thinks I should invest the time to swap over to the pinks. Thinking I should sleep on it and make a decision later.

Dave

[DaveK]

Decided to go ahead and change the injectors. Took a little over an hour, 90% of the time was spent trying to get the old ones out. New ones dropped in nicely and the car fired right up...thought did take a little bit of gas pedal. Checked for leaks and after not finding any took it for a quick spin.

The horrible bucking/miss in the 2-3k range is basically gone and driveability is much improved. Only possible complaint is the car seems to have lost a bunch of power...but maybe since it's on all 4 cyl all the time there isn't the huge kick when that 4th injector fired to life. Hoping that the ECU will mess about with some of the compensations over the next coupe of days.

Dave

[wtdash]

I'd suggest to 'reset' the ECU. Disconnect the battery or pull the main fuse in the under hood panel...and leave the dome light on....or push the brake pedal (read that online)?? ....give it 30 minutes. and then connect battery and let the ECU learn from scratch - do this on a COLD engine.. Don't touch the go pedal/drive it 'til it has got to operating temp. Then gradually get into boost over a 15 mile drive and see how it does.

It will take a few starts and more miles to even out. Hopefully you'll be back to full power.

....Also, check the CODEs to make sure those are all clear. If it's still feeling 'weak' then I'd bet you're KS fix didn't take, and you're running in 'limp mode'.

GL,
Td