EJ22 Idle issues

MY_STI · Post by **MY_STI** » Mon Feb 12, 2007 12:10 pm

Gen1 Ser2 EJ22 in an MY
Previously the engine idles beautifully, on the odd occasion it would run rough for a second then get over it (restarting/starting hot), was still getting error codes 24 (idle air control valve) and 33 (speed sensor of lack thereof).

Finally getting around to to looking for the cause of the error I though I had found it, one wiring diagram showed two wires from the IAC valve reversed (pins 1 & 2, 26 pin connector), in my eagerness I swapped them and fired it up. Not a happy engine, super rough idle and hunting bigtime.

Checking a spare ej loom and another wiring diagram revealed they were around the correct way to begin with (An intelligent person would have checked this BEFORE playing with things).

After swapping the wires back the engine now idles on two cylinders (3 & 4), at a 'steady' 1200-1500 rpm depending on temp etc. When driving you can feel the other injectors 'kick in' when the ecu comes off the idle loop.

Have tested the IAC wires for continuity, all good.
Tried another ECU, no difference.
Tried another IAC valve, no difference.

Both the IAC stepper motors measure 9 ohms between the common supply and the directional grounds (the two wires that return to the ecu) as does the stepper on the ej20g, so I think that they are all ok.

The voltage at pins 1 & 2 when idleing is the full battery voltage, documentation stats it should be around 7-9.
So the ecu is not providing any control for the valve.
Code 24 has a description of 'uses fuel cut to prevent abnormal engine speed' which sounds fitting.
Not getting any other error codes, but pluging in a fresh ecu gives code 24 instantly when the car is switch to on (not running)

I think either something else was damaged and is killing the ecu(s), or someting is else is dead and the ecu doesn't have enough information to operate correctly.

Next step is to check voltages etc for other sensors

Any other ideas? This one is really frustrating.

Sorry for the long post, though a bit of background info might help.

stamp_licker · Post by **stamp_licker** » Mon Feb 12, 2007 7:14 pm

have a look at the ignition relay.I had 24 and 35 come and go ,it would idle on 3 cylinders and run rough dropping number 1.What was happening was one side of the relay which powers that circuit would sometimes allow battery voltage and when it was playing up was only allowing about 3 volts.Since replacing the problem has gone.

vidler · Post by **vidler** » Mon Feb 12, 2007 7:23 pm

take off the idle air control soleniod unit thing, squirt the hell out of the inside with carby cleaner and get it moving freely, give it a flick or two with a screw driver to be sure but be gentle. I had the same problem when i put the EJ25 in my L series.

BaronVonChickenPants · Post by **BaronVonChickenPants** » Mon Feb 12, 2007 7:45 pm

Is there some way to reset the ecu, like 12 or 24 hours without power?

Is it possible it could have retuned itself with a bad tune to compensate for the backward IAC?

Jordan

SuBaRiNo · Post by **SuBaRiNo** » Mon Feb 12, 2007 9:21 pm

I first thought that but he has tried another ECU so that would have a fresh start... unless it was directly out of another car.... But yes leaving it disconected for a period of time would reset it and may fix it.

I think try what Vidler has said... the IAC is a common problem with these EJs. Portentially wiring it wrongly, even for an instant, has made the internal magnet force the valve fully open and jam it.

Dave

MY_STI · Post by **MY_STI** » Tue Feb 13, 2007 11:52 am

Thanks Guys,

The second ECU had been on the shelf for about 4 months, so I assumed it was well and truly back to defualts, They don't seem to be disconnected for long to forget the error codes at any rate.
Have swapped ECU's back and forward several times. Taken the cases off, no visible damage or burnt circuitry smell, haven't tested any further than that yet.
Haven't yet tried the long-winded proccess for reseting the ecu, but I doubt if it will make a difference.

Started with the IAC valve as this is where I was expecting the trouble to be. the valve itself is moving very freely and smoothly. Before and after cleaning. It was suprisingly clean to begin with.

Will have a look at the ignition relay, might replace it with two heavy duty relays for good measure.

Talasas · Post by **Talasas** » Sat May 21, 2011 11:52 pm

Huge thread dig but did you ever solve this? I have the same problem, in fact my problem is the same, cyl 1 doesn't seem to fire right sometimes. The injectors have been cleaned and are firing, the seems to b spark as well bit it may be weak. I tried to check the ignition relay today but it's in a god awful location so I wanted to know if that worked before I go taking my dashboard apart.

Talasas · Post by **Talasas** » Sun May 29, 2011 4:28 pm

Anyone?

I've gone through a crap ton of problem solving to find this bastard, I seem to have very much the same problem that stamp_licker mentioned where it only idles on 3 cylinders. It seem to be a slightly common issue as all the scraps of info I find online have similar symptoms:

- Idles on 3 cylinders only sometimes
- Cold start may be worse but often hard to re-create
- ECU Code 22 (Knock Sensor)
- ECU Code 24 (Bypass Air Control Valve (BAC Valve))
- ECU Code 35 (Purge Control Solenoid)

Now these come up from time to time, I will clear the ECU and it will crop up shortly after idling, but it might be the 2nd or 3rd time I start the engine.

To try and find the problem this is what I have done to rule out issues:

- Injectors cleaned and tested
- New spark plugs
- New ignition leads
- Replaced head gaskets, inspected valves, bores etc. (thought it might be a compression problem, alas it wasn't)
- Replaced ignition coil
- Replaced knock sensor (this was cracked and broken)
- Replaced air flow meter
- Tested TPS with replacement (original was in spec)
- Tested BAC valve, seems to be in spec but there's no information on how/when to adjust it using the screws.
- Purge control valve resistance tested and is out of spec (can't see this being major enough to idle on 3 cylinders?)

Now it seems to drop cylinder 1 when it idles funny. Everywhere else I have found information about this there has either been no reply to the OP or those who have fixed it never post how they fixed it.

Left on the to do list:

- Replace purge control valve (I doubt this will change anything except the remove the error flag for this)
- Test/replace Ignition Relay. (This one's a bitch, how the hell do you get to it?)

Talasas · Post by **Talasas** » Sun May 29, 2011 6:27 pm

Okay I've removed the ignition relay and it seems to test fine. I've since found an epic thread on USMB about how it's some sort of electrical noise to the ECU. There is no follow up on how to fix it but man what a colossal PITA.

SuBaRiNo · Post by **SuBaRiNo** » Sun May 29, 2011 8:02 pm

Is this on an ej converted car or factory lib? I know there is a lot of things that can cause this problem but recently I had an ej engine behave like u are describing and it was a faulty temp sensor. There are 2 on the ej22. One is for the dash (single wire) the other is for the ecu (2 wire). Check the ecu one.

Also have u checked fuel pressure? Could be fuel pressure reg problem or fuel pump or even blocked fuel filter. Also make sure fuel isn't making it's way back up the engine evaporate lines effectively flooding the engine... I have seen this on an ej conversion and if felt like a miss. There are no codes relating to the fuel system but I'm sure fuel problems would cause other unrelated codes.

Some more history or info on the car may help.

Dave

Talasas · Post by **Talasas** » Sun May 29, 2011 8:36 pm

It's on a factory stock 89 Liberty Auto. 300,000 kms. Only had the car a few years and it hasn't run much over that time, I bought it with this problem already in place but it's not the first Liberty I've owned.

It doesn't feel fuel related so much as it does spark related, but I'll humour anything at this stage. It's still a concern that it's intermittent and that turning the engine off and back on can sometimes rectify it. This is why I'm lead to believe it might be the issue that cropped up here:

http://www.ultimatesubaru.org/forum/sho ... hp?t=19616

If you look on page 3 a post by "PacMan" states he found an issue with the ECU that he was designing a fix for. Unfortunately he never went into detail about it. I'm also starting to think this problem occurs on Series 1 Auto ECUs only.

I haven't checked the fuel pressure or flow yet. The only part of the fuel system I have checked are the injectors and fuel lines.

Coolant temp sensor checked out okay, I did forget to mention that on my list (was going by memory).

T'subaru · Post by **T'subaru** » Sun May 29, 2011 11:03 pm

This might be worth checking out.
http://www.ultimatesubaru.org/forum/sho ... p?t=109444

Talasas · Post by **Talasas** » Mon May 30, 2011 12:37 am

I had a read, but I don't seem to find how it's related? It covers a converted EJ22 running an auto ECU on a manual without a check engine light hooked up. Their problem was stalling, mine doesn't stall - it idles on 3 cylinders and jumps to 4 once the revs pick up beyond a certain point.

RSR 555 · Post by **RSR 555** » Mon May 30, 2011 2:23 am

Grab yourself a copy of the WSM and start testing sensors with a multimeter as per manual. I'm thinking Ignition relay (I know you have tested it) but you'll need use a new one to be sure. I have a new one that I use when testing customers cars and 9 out of 10 times it solves thier issues. Also, when you say you have replace the other items.. does this mean you brought new ones or secondhand items?

Talasas · Post by **Talasas** » Tue May 31, 2011 7:30 pm

Some new, some from a clean, known working Liberty I have. I've been taking off spare parts from that car and putting them on the one that's playing up to rule out that part.

Talasas · Post by **Talasas** » Sun Jun 05, 2011 6:22 pm

Okay, just as a follow up, I'm pretty confident I've solved my poor idle problem. It was the Ignition Relay and I have come up with a solution where you can replace the Jideco relay with a pair of aftermarket relays and it seems to work nicely. I will write up a guide on how to do this and post it in a new thread so others can fix it.

I also have a thread about this on USMB so I will also post it on there for those interested.

YouTube · Post by **El_Freddo** » Mon Jun 06, 2011 12:49 am

Talasas wrote: I will write up a guide on how to do this and post it in a new thread so others can fix it.

Don't forget to drop the link in here too so that others may follow it up from this thread if they have the same issue

Cheers

Bennie

Talasas · Post by **Talasas** » Tue Jun 14, 2011 11:18 pm

Here's a link to the guide:

showthread.php?t=19809